Better support for binary groovy files

Currently, when viewing binary files that come from groovy sources in a class file editor, there are several problems and they all come from the fact that the generated byte code does not cleanly match with the original source code. The line number mappings do not appear to be the major cause of the issue, but rather the fact that properties and methods are named differently in the binary than in the source.

For example, setting breakpoints is problematic, navigation using the outline view often does not work, Java search will often miss some references, and the outline view will show many generated methods that do not appear in the source.