Fix problem in clipping the view for changes

To account for the fact that the set of folded lines might be
different post-change and pre-change.
Fix delayed update of scroll height

Due to some elements still being stuck at the old height.
Initialize doc before display

Slightly simplifies constructor logic.
Fix bug in drawing selection behind collaping widget at end of line
Remove stray console.log
[linter] Warn on console.* and debugger statements
[sublime keymap] When splitting selection, ignore last line if selection ends at beginning of line