GROOVY-3457: Fixing bug where line number of template error was incorrectly reported

o Added more granular unit tests correct line numbers on
  exceptions thrown when parsing/executing a template
o Added context reporting so that three context lines of code is
  now added to the thrown template errors even if it is a template
  parse (vs execution) error.
o Added and fixed various javadocs for StreamingTemplateEngine
GROOVY-3457: Cleaning white space
GROOVY-3457: Fixing javadocs for StreamingTemplateEngine
GROOVY-7186: Close URLConnection getInputStream() after testing for availability
Patch for issue GROOVY-7043
GROOVY-7198: Override annotation should be removed from methods before
adding them to Trait$Helper class during AST transformation
Create 'Override' annotation ClassNode and using it for filtering Helper
method annotations
Merge pull request #556 from armsargis/GROOVY-7198

GROOVY-7198: Remove Override annotation from Trait$Helper
GROOVY-7210: The type checker doesn't check for getAt/putAt for primitive arrays if the index type is boxed
GROOVY-7175: Add List.withIndex()
GROOVY-7175: add DGM withIndex methods
minor doco typo
GROOVY-7175: add DGM indexed methods (has index, value ordering)
GROOVY-7169: Incorrect least upper bound in case both types are arrays
Merge pull request #559 from paulk-asert/groovy7175

Groovy7175
GROOVY-7171: Add List.getIndices()
GROOVY-7171: DGM getIndices methods (changed List to Collection and also added object array for completeness)
GROOVY-6952: Add List.removeAt(int) and Collection.removeElement(Object), because for List<Integer>, List.remove(int) and Collection.remove(Object) are troublemakers.
GROOVY-6952: Add List.removeAt(int) and Collection.removeElement(Object)
GROOVY-7212: Upgrade JUnit to 4.12