REVIEW-1294 reuse JavaVersion enum for targetJdk in PmdExtension
REVIEW-1296: mark dashboard plugin as incubating.
REVIEW-1296: tweak GenerateBuildDashboard task to set didwork false if no dashboard is generated.
REVIEW-1297: add more test coverage; rename DistributionsContainer -> DistributionContainer.
REVIEW-1297 some fixes on distribution plugin
- move evaluation of valid distribution name to consumer
- fix typo in error message
- rename DistributionsContainer -> DistributionContainer
- clean up DistributionContainer (remove add methods)
- remove unused DistributionExtension
REVIEW-1299: some more tweaks on Zip compression support

- use deflate as a default (as done in previous gradle versions)
- fix javadoc (mixed up DEFLATE and STORE)
- renamed Zip.contentCompression -> Zip.entryCompression
- renamed Compressor to ArchiveOutputStreamFactory
- renamed ContentsCompression to ZipEntryCompression
- removed ZipOutputStream.setMethod in ZipCopySpecVisitor
REVIEW-1302: fix findbugs maxHeapSize dsl documentation.
REVIEW-1298: more cleanup on DistributionPlugin and JavaLibraryDistributionPlugin
- remove distribution extension in JavaLibraryDistributionPlugin
- introduce Distribution.baseName property like described in according spec
- updated release notes