Added autocomplete for constructors.

This was done by adding an additional case to the completion logic
in ScalaCompletions.

To avoid problems with completion overwrites, similar to Eclipse Java
only tooltips are shown for constructor completion.

A known defect is the ability to complete constructors of classes with
mixins on the same line. See #1001950

Fix #1001272
Added note about PR getting close after 2 weeks of inactivity
Enable editor preferences

Rename `DebugPreferenceInitializer` to `EditorPreferenceInitializer`

Fixes #1001965
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
Plugs in IJavaReconcilingListeners

Better interfaces
Essential tweaks in Problem annotation safety
Narrows down invalidated text region
Fix stale / ill-formatted code.

Fixes #1001454
De-activated test requiring ui
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
Normalises w.r.t deprecation and namespaces

reloads before interactive demands

adressing PR comments

cosmetics
constrains optimistic cast in ScalaReconciliationStrategy

more eager initialReconcile
Leave the reconciler delay at platform default
Makes (askL|l)oadedType(d)? unload new units after use by default

Fixes #1001388
Rename methods that have nothing to do with the PC, yet start with 'ask'

While this needs not be a strict convention, the less 'ask[A=Z]\w+' mathods that don't call the PC the better.<
Tie reload scheduling to the PC access methods.

Non-modularized, non-thread-unicity-enforcing version (for SH test complicance).
Adds askOptionWithPriorReload
weaken loadedType agressivity on findOccurrences
Reestablishes Quickfix functionality

Provides an IcompilationUnit for ProblemAnnotations created out of reconciliation