additional test: @CompileStatic with @Singleton
GROOVY-6909: @CompileStatic in combo @WithXXXLock transform is broken
Merge branch 'GROOVY_2_3_X' of https://github.com/groovy/groovy-core into GROOVY_2_3_X
additional test: @CompileStatic plus @Synchronized
additional test: @CompileStatic plus @Newify
additional test: @CompileStatic plus @Lazy
additional test: @CompileStatic plus @Delegate
additional test: @CompileStatic plus @Delegate (accommodate toString() format differences)
GROOVY-6910: @CompileStatic in combo with @IndexProperty transform is broken
clean up imports
GROOVY-6913: additional cleanup for @Immutable combined with @CompileStatic
additional test: @CompileStatic plus @ConditionalInterrupt
Add macros for JDK and Groovy JDK links.

This extends the current support for Groovy API macros to the JDK and the
Groovy JDK. It also allows the author to do some extra things:

* Add a custom label for a link using square brackets
* Link to the index page

As an example, you could link to the Groovy JDK index page with a dedicated
label using

    gjdk::index[Groovy JDK]

Even if you don't want to use a custom label, the square brackets can help
delimit class names at the end of a sentence:

    gapi::groovy.xml.MarkupBuilder[].

This should help immensely with cross-documentation links and I'm using it
already in the Groovy Development Kit chapter.