Add utility function to manipulate the new use block state bitmask.
Get rid of TextBlockUserData for symbol mathing code

(pyqode.python auto indent mode will need adaptations)
Fix AttributeError in some strange circumstances
Get rid of TextBlockUserData for cc_disabled_zone
Remove TextHelper.block_user_data

This finish the taks for pyqode.core, pyqode.python and OpenCobolIDE must be adapted in consequence.
Fix return value and improve API to suite pyqode.python requirements
Fix a few incoherencies and update doc and comments
Merge pull request #140 from pyQode/feature/block_state

Ready to (re)implement code folding