Removed unnecessary BufferedWriter/BufferedOutputStream as described in GROOVY-6314 issue
Added methods:
- void append(Path file, Reader reader)
- void append(Path file, Reader reader, String charset)
- void append(Path file, Writer writer)
- void append(Path file, Writer writer, String charset)
Added @since javadoc annotation
GROOVY-6621 fix Node#text when value is NodeList

by accounting for non-String children elements
existing difference from o.w.d.Document
Merge branch 'master' into GROOVY-6621-Node-text-when-NodeList-value
in preparation for moving the original tests
move NodeTests to main project
update for changes to text() method
Updated GroovyDoc to use new templates
Merge branch 'master' into GROOVY-6621-Node-text-when-NodeList-value
First experiment for a @Trait AST transformation
Trait experiment, phase 2:
   * replace delegate approach with "multiple inheritance like" approach
   * support for fields in traits
   * helper class now uses static methods and initializer method
   * if fields are defined, a helper interface is defined too
   * NO SUPPORT FOR FIELDS ON LHS OF ASSIGNMENTS YET
   * no support for trait inheritance
Trait experiment, phase 2:
   * make sure generated getters appear first to avoid potential NPE
Code cleanup for trait AST transformation
   * remove fields from helper class (not needed anymore)
   * remove the helper abstract method annotation (replaced with good old abstract methods)
   * do not generate anything for synthetic methods
Trait experiment: initial support for properties and assignments
Trait experiment: initial support for closures defined in traits
Fixed IncompatibleClassChange error with precompiled traits
Adding a trait keyword

Conflicts:
	src/test/org/codehaus/groovy/transform/TraitASTTransformationTest.groovy
Make use of the trait keyword