Summary:
toolbar popup displays
restore caret protection on contenteditable
BAD - can't use cursor saving and restoring with react :(
_findNode works
saves and restores cursor state
contenteditable fixes to support cursor
comments on cursor
initial undo manager
extract undo manager and move up in stack
make undo manager a mixin
adding selection snapshots in composer
fixes in undo manager
selection saves selection states properly
move UndoManager and fix draft
selection state can now select backwards
selection works backwards and click not overridden
change bold class to allow for bolding and unbolding
styling of hover component
can set links in composer
bold and italic clicking works. text seleciton works
show link modal on hover
selection fixes
Test Plan: TODO
Reviewers: bengotow
Reviewed By: bengotow
Differential Revision: https://review.inboxapp.com/D1249
