(Bug and fix from Martin Lippert)

- Enhanced structure model support.
- *Incremental* structure model support written and tested (currently switched off, see incModelTests.xml)
- -showWeaveInfo compiler option
- existence of a 'runtimetest' surfaced through relationships
- UI can determine if errors/warnings came from DEOWs.
- Code to enable type mungers to remember source locations written (currently switched off)

   build cancel during weaving

a cruise control driven build.

ensure messages are associated with source wherever possible

removed unused imports, local variables, and private methods
(still there, just commented out).

   XLint warning for call PCD's using subtype of defining type 

also added extraSourceLocations to IMessage+ for
message with multiple source lines

- Added getDetails() to messages.  This String corresponding to thisJoinPointStatic part can be used by tools that need to display additional info.

In the process of this many changes were made to try to make
keeping up with the Eclipse-JDT code base as easy as possible in
the future.

This adds an optional "context" String to IMessage.
The IMessage creator should create a context String (or use an implementation that lazily creates one).
The IMessage client can render their messages without context embedded in the message field.

Emitting source context from the weaver will be harder.
Using file and start/end line will probably work, since tool clients can map to any available source file paths.
(BcelSourceContext and BcelShadow can be updated with end from range.)

end line.

clears up a huge set of warnings in Eclipse so that you
can see the wood for the trees!

want to abort w/o message, and to always stuff in a stack trace