GROOVY-3298: Support multiple labels on the same statement
GROOVY-6945: Some DGM Collection improvements
Merge pull request #483 from paulk-asert/groovy6945

GROOVY-6945: Some DGM Collection improvements
GROOVY-6948: NioGroovyMethods don't work under JDK6
minor refactor (code cleanup)
GROOVY-6953: Fix regression in static compilation wrt to @DelegatesTo and maps
GROOVY-6955: Regression in the way setters are called if @DelegatesTo references a Java class
GROOVY-6963: groovydoc should honour the {@docRoot} javadoc tag
minor refactor: remove some checkstyle warnings
GROOVY-6964: Build on Windows.
Building on Windows was not supported because JarJarTask does not release a file lock.
Please read http://groovy.329449.n5.nabble.com/Build-issue-with-groovy-core-master-td5719619.html for the detail.
I fixed this problem.
Merge pull request #486 from yukoba/WindowsBuild

GROOVY-6964: Build on Windows
minor refactor: remove javadoc warning
GROOVY-6962: Fix IllegalAccessException if the target public method belongs to a package private class
GROOVY-6965: Fix ClassCastException during type checking
GROOVY-6930: Fixed possible infinite wait during extension module scanning if an error occurs during contruction of the meta-model of a class
GROOVY-6903: Add null check in getProperties()
Minor fixes.

1. This is a @Deprecated method and very meaningless to modify, but I changed internal cast of Collection.multiply(Number) from List to Collection. This was a bug.
2. Removed meaningless @SupressWarning of Collection.grep().
3. << to &lt;&lt; in JavaDoc.
4. Fixed some wrong JavaDoc.
GROOVY-6961: fix wrong generics type extraction for extension methods by using the custom declared class instead of backing node
Merge pull request #489 from yukoba/MinorFix

Minor fixes
Introduce a BytecodeDumper class for reuse in tests