Use sbt for PR validation builds.

# Improve version handling in the sbt build:

The new settings `baseVersion` and `baseVersionSuffix` make it easier
to set version numbers for different kinds of builds in a consistent
way without e.g. having to first get a git SHA outside of sbt.

The new task `generateBuildCharacterPropertiesFile` writes the file
`buildcharacter.properties` to the root dir. The format is compatible
with the same file produced by the ANT build but it only contains a
subset of the properties, in particular the Maven version, which is
needed in publishing scripts and passed around between different
Jenkins jobs as `jenkins.properties`.

SHAs in version numbers are consistently shortened to 7 digits (as used
by git and github). Previously we used 7 digits in Maven snapshot
version numbers but 10 digits in canonical and OSGi version numbers.

# Add Jenkins script support to the sbt build:

The new command `setupPublishCore` takes the PR validation snapshot
repository as an argument and changes the required settings for the
`publish-core` build (use SHA-SNAPSHOT versioning, compile with
optimization enabled, do not publish scaladoc sets)

For example, the following command can be used to generate
`buildcharacter.properties` with the version numbers needed for PR
validation builds:

  sbt setupPublishCore dummy generateBuildCharacterPropertiesFile

The sbt build will now automatically detect and use a “~/.credentials”
file with the credentials for publishing to a remote repository.

# Call sbt from `publish-core`:

The correct`$SBT_CMD` is set directly in `bootstrap` and used by
`publish-core` to first generate `buildcharacter.properties` and then
build and publish. Parsing the git revision, computing a version
number and getting binary dependencies are no longer required in the
script. This is all done in the sbt build.

1 files changed, 3 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
index d6571a377f..061cd274ac 100644
--- a/.gitignore
+++ b/.gitignore
@@ -26,6 +26,9 @@
 /build.properties
 /buildcharacter.properties
 
+# might get generated when testing Jenkins scripts locally
+/jenkins.properties
+
 # target directories for ant build
 /build/
 /dists/