No longer cursor insertion in SessionController.startEditing, fix cursor removal where missing
Fix incomplete destroy of SessionController
Add gui.EventManager.destroy()
Fix InputMethodEditor.destroy not unsubscribing from all events
Merge pull request #387 from kossebau/fixStartEndEditing

Unbreak Editor loading a new document with same canvas, but new session & controllers
Clear the stylesheets in OdfCanvas inside refreshOdf
Merge pull request #386 from kossebau/cleanStylesOnRefreshOdf

Clear the stylesheets in OdfCanvas inside refreshOdf
Split the word boundary filter out of SelectionController

Primary intent is to reduce the size of the selection controller class,
in preparation for some additional fixes to aid word boundary detection
in non-english languages.
Rewrite move & select via word boundaries to use a step iterator
Rewrite range-based word boundary expansion to use step iterators
Cope with non-latin alphabets when searching for word boundaries

This has been sourced from http://apps.timwhitlock.info/js/regex, which
creates these sets using the cset JS library. The set includes all
punctuation components only.

Addresses issue #268
Reword variable names to improve code readability
Move WordBoundaryFilter to the ODF namespace to allow for wider reuse
Merge pull request #353 from peitschie/word-boundary

Improve word boundary detection in non-english charsets
Remove superseded SelectionMover.countStepsToPosition
Use cached-based conversion rather than SelectionMover.move
Remove superseded SelectionMover.isPositionWalkable
Adjust StepsTranslator behaviour

When the requested number of steps is beyond the document end in
convertStepsToDomPoint, this will now return the last walkable step
rather than the current iterator position. This closes a slight hole
where asking for a step beyond the document would return an unwalkable
position.
Reducing usages of SelectionMover.countSteps

SelectionMover.countSteps has been replaced by step iterators and other
more performant solutions.
Remove last usages of OdtCursor.move from tests

All remaining OdtCursor tests are really testing other parts of the system that
are already covered in their own unit tests. For now, this file has been removed
and should be replaced later when OdtCursor gains additional tests.