The build.xml script included with the ecj source erroneously includes
the signature files from the source jar in the newly built ecj jar

The newly built ecj jar also reports its own version as
"bundle_qualifier, bundle_version" due to not including the correctly
interpolated version of the properties file.

This change fixes the build.xml script and adjusts the
"batch-compiler-src" execution in the pom.xml accordingly.

Change-Id: Ic03561b5f01ea110ec2519e0271dbd37ec604776
Signed-off-by: Mat Booth <mat.booth@redhat.com>