Added check for /usr/libexec/java_home

This is the preferred way of choosing a JVM on OS X

http://developer.apple.com/library/mac/#qa/qa1170/_index.html
GROOVY-5632: Closure default params can cause BUG! exception in phase 'class generation'
minor refactor to adjust submodule dependencies
GROOVY-5191: Running script with '--enoding' param and some script parameters (prepare groundwork for deprecating PosixParser)
GROOVY-5191: Running script with '--enoding' param and some script parameters
Make @CompileStatic aware of type checking extensions too
  * doesn't make extensions compatible with compile static in general
  * but allows the user to throw more errors than the regular type checker
GROOVY-5554: Implementation of DelegatingCustomizer and SourceAwareCustomizer
    * DelegatingCustomizer is a compilation customizer which delegates execution to another customizer, using the compile phase of the delegate. This is the base class for implementing guards for customizers.
    * SourceAwareCustomizer is an implementation of a delegating customizer supporting various checks on source unit, for example the file name extension, the base name (before the extension) of the file or even a custom check on the SourceUnit
GROOVY-5553: Provide a builder for compilation customizers
GROOVY-5503: Replace CompilerConfiguration#customizers with a static method CompilerCustomizationBuilder#withConfig
Rename -configuration option to -configscript
add some generics information to have less casts
extend alias annotations to allow the usage of annotations on the alias
fix generics
enforce final class for annotation alias, let the code remove super classes, interfaces and modifiers for enum, annotation, abstract and itnerface
improve documentation for alias annotation code
Remove @Override for compatibility
GROOVY-5786: make the global closures map be configurable through the script context. This allows letting the engine use weak or woft references for this map instead of hard references.
Added an ErrorCollector stack to make it possible to have a totally silent type checking
Fix more @Override issues
Fast exit from method ClassCompletionVerifier.checkMethodForWeakerAccessPrivileges