Prepare build for inclusion of java8-compat

<h1>Allow mixed builds in ant</h1>

The `JFunction` classes depend on the `FunctionN` traits, so the
Java compiler needs the Scala library on the classpath.

At the same time, while compiling the Scala library, the symbols for
`JFunction` classes need to be available to emit indy-lambda closures.
Therefore we pass the `JFunctions` as Java sources while compiling the
Scala library.

<h1>Upgrade versions of osgi tools</h1>

Set the required java version in bnd files (JavaSE-1.8).

Introduce `scala-swing.version.osgi` as a quick hack to
allow manually deriving an osgi-friendly version number
for the `scala-swing.version.number`. The latter is used
to resolve the artifact, the osgi version is just so we
can generate a bundle that osgi will accept.

Bnd 1.50 doesn't work with Java 8 classfiles, so upgrade to 2.4.1.

Also upgrade all other tools to make tests pass.
For `org.eclipse.osgi` we moved to the group ID `org.eclipse.tycho`,
where there's a newer version available. The osgi tests would fail
with the most recent version available in the `org.eclipse.osgi` groupID.

The new version of bnd only copies *classfiles* from the
original into the resulting jar, while the old version also copied
all other files. This caused osgi test failure with a `NoClassDefFound`,
which was really due to a `NumberFormatException` in `ScalaVersion`,
as it couldn't find the properties file to parse the version in...

Include resources from source jar into osgi bundle as follows:
```
  Include-Resource: @@SOURCE_JARNAME@
```

This makes bnd copy all resources from the source jar. I ran the
following on the osgi artifacts of this branch, and on 2.11.x:

```
for f in `find build/osgi -name '*.jar' -a -not -name '*src.jar'`; do unzip -l $f | grep -v '\.class' ; done
```

Comparing the two file lists, things look OK:
https://gist.github.com/lrytz/be08db051a53eded192d

1 files changed, 19 insertions, 4 deletions

diff --git a/build-ant-macros.xml b/build-ant-macros.xml
index d0c9c4d310..868fb41cce 100644
--- a/build-ant-macros.xml
+++ b/build-ant-macros.xml
@@ -202,7 +202,9 @@
     <!-- overrides the output directory; used when building multiple projects into the same directory-->
     <attribute name="srcdir" default="@{project}"/>
     <attribute name="java-excludes" default=""/>
+    <attribute name="mixed" default="NOPE"/>
     <sequential>
+      <local name="mixed.true"/><condition property="mixed.true"><equals arg1="@{mixed}" arg2="true"/></condition>
       <!-- TODO: detect zinc anywhere on PATH
            use zinc for the quick stage if it's available;
            would use it for locker but something is iffy in sbt: get a class cast error on global phase -->
@@ -220,12 +222,14 @@
             <then>
               <scalacfork taskname="@{stage}.@{project}" jvmargs="${scalacfork.jvmargs}" compilerpathref="@{with}.compiler.path" destdir="${build-@{stage}.dir}/classes/@{destproject}" srcdir="${src.dir}/@{srcdir}" params="${scalac.args.@{stage}} @{args}">
                 <include name="**/*.scala"/>
+                <include name="**/*.java" if="mixed.true"/>
                 <compilationpath refid="@{stage}.@{project}.build.path"/>
               </scalacfork>
             </then>
             <else>
               <scalacfork taskname="@{stage}.@{project}" jvmargs="${scalacfork.jvmargs}" compilerpathref="@{with}.compiler.path" destdir="${build-@{stage}.dir}/classes/@{destproject}" srcdir="${src.dir}/@{srcdir}" srcpath="@{srcpath}" params="${scalac.args.@{stage}} @{args}">
                 <include name="**/*.scala"/>
+                <include name="**/*.java" if="mixed.true"/>
                 <compilationpath refid="@{stage}.@{project}.build.path"/>
               </scalacfork>
             </else>
@@ -270,6 +274,7 @@
     <attribute name="includes" default="comp.includes"/>
     <attribute name="java-excludes" default=""/>
     <attribute name="version" default=""/>
+    <attribute name="mixed" default="NOPE"/>
     <!-- non-empty for scaladoc: use @{version}.version.number in property file-->
     <sequential>
       <staged-uptodate stage="@{stage}" project="@{project}">
@@ -279,9 +284,18 @@
         <do>
           <stopwatch name="@{stage}.@{project}.timer"/>
           <mkdir dir="${build-@{stage}.dir}/classes/@{project}"/>
-          <staged-javac stage="@{stage}" project="@{project}" excludes="@{java-excludes}"/>
-          <!-- always compile with javac for simplicity and regularity; it's cheap -->
-          <staged-scalac with="@{with}" stage="@{stage}" project="@{project}" srcpath="@{srcpath}" args="@{args}" java-excludes="@{java-excludes}"/>
+          <if>
+            <equals arg1="@{mixed}" arg2="true"/>
+            <then>
+              <staged-scalac with="@{with}" stage="@{stage}" project="@{project}" srcpath="@{srcpath}" args="@{args}" java-excludes="@{java-excludes}" mixed="@{mixed}"/>
+              <staged-javac stage="@{stage}" project="@{project}" excludes="@{java-excludes}"/>
+            </then>
+            <else>
+              <staged-javac stage="@{stage}" project="@{project}" excludes="@{java-excludes}"/>
+              <!-- always compile with javac for simplicity and regularity; it's cheap -->
+              <staged-scalac with="@{with}" stage="@{stage}" project="@{project}" srcpath="@{srcpath}" args="@{args}" java-excludes="@{java-excludes}"/>
+            </else>
+          </if>
           <if>
             <equals arg1="@{version}" arg2=""/>
             <then>
@@ -474,7 +488,8 @@
           <filter token="SCALA_COMPILER_INTERACTIVE_VERSION" value="${scala-compiler-interactive.version.number}"/>
           <filter token="XML_VERSION"                value="${scala-xml.version.number}" />
           <filter token="PARSER_COMBINATORS_VERSION" value="${scala-parser-combinators.version.number}" />
-          <filter token="SCALA_SWING_VERSION"        value="${scala-swing.version.number}" />
+          <filter token="SCALA_SWING_VERSION"        value="${scala-swing.version.osgi}" />
+          <filter token="SOURCE_JARNAME"             value="${@{project}.targetjar}"/>
         </filterset>
       </copy>
       <bnd classpath="${@{project}.jar}" eclipse="false" failok="false" exceptions="true" files="${build-osgi.dir}/${@{project}.name}.bnd" output="${build-osgi.dir}"/>