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

8 files changed, 16 insertions, 8 deletions

diff --git a/src/build/bnd/scala-compiler-doc.bnd b/src/build/bnd/scala-compiler-doc.bnd
index 9d6d0304d1..5b662e8cef 100644
--- a/src/build/bnd/scala-compiler-doc.bnd
+++ b/src/build/bnd/scala-compiler-doc.bnd
@@ -4,4 +4,5 @@ ver: @SCALA_COMPILER_DOC_VERSION@
 Bundle-Version: ${ver}
 Export-Package: *;version=${ver}
 Import-Package: scala.*;version="${range;[==,=+);@VERSION@}",*
-Bundle-RequiredExecutionEnvironment: JavaSE-1.6, JavaSE-1.7
+Bundle-RequiredExecutionEnvironment: JavaSE-1.8
+Include-Resource: @@SOURCE_JARNAME@
diff --git a/src/build/bnd/scala-compiler-interactive.bnd b/src/build/bnd/scala-compiler-interactive.bnd
index 07e3de35b0..fbfff60801 100644
--- a/src/build/bnd/scala-compiler-interactive.bnd
+++ b/src/build/bnd/scala-compiler-interactive.bnd
@@ -4,4 +4,5 @@ ver: @SCALA_COMPILER_INTERACTIVE_VERSION@
 Bundle-Version: ${ver}
 Export-Package: *;version=${ver}
 Import-Package: scala.*;version="${range;[==,=+);@VERSION@}",*
-Bundle-RequiredExecutionEnvironment: JavaSE-1.6, JavaSE-1.7
+Bundle-RequiredExecutionEnvironment: JavaSE-1.8
+Include-Resource: @@SOURCE_JARNAME@
diff --git a/src/build/bnd/scala-compiler.bnd b/src/build/bnd/scala-compiler.bnd
index 2bd24d780d..3e60c4973c 100644
--- a/src/build/bnd/scala-compiler.bnd
+++ b/src/build/bnd/scala-compiler.bnd
@@ -9,4 +9,5 @@ Import-Package: jline.*;resolution:=optional, \
                 scala.xml.*;version="${range;[====,====];@XML_VERSION@}";resolution:=optional, \
                 scala.*;version="${range;[==,=+);${ver}}", \
                 *
-Bundle-RequiredExecutionEnvironment: JavaSE-1.6, JavaSE-1.7
+Bundle-RequiredExecutionEnvironment: JavaSE-1.8
+Include-Resource: @@SOURCE_JARNAME@
diff --git a/src/build/bnd/scala-library.bnd b/src/build/bnd/scala-library.bnd
index 7eb4fa4b2a..e211c5d1ad 100644
--- a/src/build/bnd/scala-library.bnd
+++ b/src/build/bnd/scala-library.bnd
@@ -4,4 +4,5 @@ ver: @VERSION@
 Bundle-Version: ${ver}
 Export-Package: *;version=${ver}
 Import-Package: sun.misc;resolution:=optional, *
-Bundle-RequiredExecutionEnvironment: JavaSE-1.6, JavaSE-1.7
+Bundle-RequiredExecutionEnvironment: JavaSE-1.8
+Include-Resource: @@SOURCE_JARNAME@
diff --git a/src/build/bnd/scala-parser-combinators.bnd b/src/build/bnd/scala-parser-combinators.bnd
index ef8646cbd0..515084f4a8 100644
--- a/src/build/bnd/scala-parser-combinators.bnd
+++ b/src/build/bnd/scala-parser-combinators.bnd
@@ -4,4 +4,5 @@ ver: @PARSER_COMBINATORS_VERSION@
 Bundle-Version: ${ver}
 Export-Package: *;version=${ver}
 Import-Package: scala.*;version="${range;[==,=+);@VERSION@}",*
-Bundle-RequiredExecutionEnvironment: JavaSE-1.6, JavaSE-1.7
+Bundle-RequiredExecutionEnvironment: JavaSE-1.8
+Include-Resource: @@SOURCE_JARNAME@
diff --git a/src/build/bnd/scala-reflect.bnd b/src/build/bnd/scala-reflect.bnd
index e4bc54e52e..59db311f8d 100644
--- a/src/build/bnd/scala-reflect.bnd
+++ b/src/build/bnd/scala-reflect.bnd
@@ -6,4 +6,5 @@ Export-Package: *;version=${ver}
 Import-Package: scala.*;version="${range;[==,=+);${ver}}", \
                 scala.tools.nsc;resolution:=optional;version="${range;[==,=+);${ver}}", \
                 *
-Bundle-RequiredExecutionEnvironment: JavaSE-1.6, JavaSE-1.7
+Bundle-RequiredExecutionEnvironment: JavaSE-1.8
+Include-Resource: @@SOURCE_JARNAME@
diff --git a/src/build/bnd/scala-swing.bnd b/src/build/bnd/scala-swing.bnd
index f8b50baa91..24cd9f6f90 100644
--- a/src/build/bnd/scala-swing.bnd
+++ b/src/build/bnd/scala-swing.bnd
@@ -4,4 +4,5 @@ ver: @SCALA_SWING_VERSION@
 Bundle-Version: ${ver}
 Export-Package: *;version=${ver}
 Import-Package: scala.*;version="${range;[==,=+);@VERSION@}",*
-Bundle-RequiredExecutionEnvironment: JavaSE-1.6,JavaSE-1.7
+Bundle-RequiredExecutionEnvironment: JavaSE-1.8
+Include-Resource: @@SOURCE_JARNAME@
diff --git a/src/build/bnd/scala-xml.bnd b/src/build/bnd/scala-xml.bnd
index 01bf0144eb..b7b19824e8 100644
--- a/src/build/bnd/scala-xml.bnd
+++ b/src/build/bnd/scala-xml.bnd
@@ -4,4 +4,5 @@ ver: @XML_VERSION@
 Bundle-Version: ${ver}
 Export-Package: *;version=${ver}
 Import-Package: scala.*;version="${range;[==,=+);@VERSION@}",*
-Bundle-RequiredExecutionEnvironment: JavaSE-1.6, JavaSE-1.7
+Bundle-RequiredExecutionEnvironment: JavaSE-1.8
+Include-Resource: @@SOURCE_JARNAME@