Minor changes to annotations.
Fixed a lot of parsing bugs

A large part of the parsing bugs were due simply to the fact that the parser wasn't being given enough context to figure out what was not html/default code. So, instead of trying to being smart for efficiency sake, the whole document is reparsed each time now (instead of the dirty subregions, as before).
Fixed bugs causing annotations in right ruler to not disappear.

The fix was to simply not use SSE's IReporter to report messages. It was providing absolutely no functionality (that I could find/see) that adding markers didn't do, except for the bug!

Also wrapped the marker creation code in a try-finally block to insure that we release the model no matter what.
EditorHelper.findEditorOfDocument should search all workbench windows
Removed unneeded code in the ModelParser

The code that's being removed was incorrect to begin with, and thus wasn't having any effect. The editor behaves as expected without it. I've found that the implementation of all the DOM stuff is used for DOM (aka HTML) validation. Thus, when adding HTML validation support is when this part of the implementation will need to be made specialised to be scala template syntax aware.
Removed usage of withCurrentEditor in structured editing code & fix type erasure problem in findEditorOfDocument.