Fixes bug in UndoManager where entering text while redo stack is not empty causes error. The error is caught in record and therefore the undo and redo stacks are cleared. The error specifically occurs because the 'oldDelta' does not match the editor state, and more specifically when that means the oldDelta lengths are incorrect. This change causes the oldDelta to be updated whenever the UndoManager has an undo or redo triggered.
fix bug where paste does not overwrite
unnecessary double clear
Cleanup

There's no reason getSelection will not be defined in the platforms we
are supporting
fix typo
Use constants

Still need to get rid of 'silent' references in selection.coffee
Remove comment (per jchen) and switch to using CoffeeScript style instance variable references (@).
Remove JS style semicolon; I'm too used to JS
Merge pull request #231 from brettPeriscopic/fix-undo-clear

Fixes bug in UndoManager where entering text while redo stack is not empty
Merge branch 'develop' of github.com:quilljs/quill into develop
Save and restore window scroll position on paste

Closes #222
event callback this should be event target
Reduce console output in advanced demo
upgrade rich-text

Fixes #217
upgrade sauce platforms
jade will use double quotes for attributes

so we need to use single quotes to avoid:
<option value="Monaco, "Courier New", monospace">Monospace</option>
avoid unnecessarily changing dropdown values
Fix #224
register multiple hotkeys at once
Update active formats after special keys

Closes #216