Moved askReload calls to the Eclipse reconciler mechanism.

You can now register files for reloading in ScalaPresentationCompiler.scheduleReload
They are flushed at reconciliation, and reconciliation updates the error annotations

Fixing indentation.
proper structure for ErrorAnnotation update
De-activated test pending reimplementation of Eclipse model tests
Work on PR comments:better interfacing, plugging on IJavaReconcilingListeners
Essential tweaks in Problem annotation safety
Narrowed down invalidated text region
Fixed ``SemanticHighlightingPositionsTest``

With the new reconciliation strategy implementation, compilation units are not
reloaded by the presentation compiler at every buffer change. Hence, in the
semantic highlighting positions tests, we need to manually force the reload of
the unit after its content is changed, or the tests will fail because the
semantic highlighting reconciler would be performed on the old unit's content.

Reload the unit after its content is replaced