Merge remote-tracking branch 'sf_booktype/2.0'

Conflicts:
	lib/booktype/apps/edit/static/edit/js/aloha/plugins/booktype/linkbooktype/lib/linkbooktype-plugin.js
BK-951 Remove code for selecting predefined style
BK-952 Create and destory tooltips as Chapter tab is shown and hidden
BK-954 Positioning cursor when the chapter is open is broken
Merge remote-tracking branch 'sf_booktype/2.0'
redo/undo works - needs way more testing and cursor positioning
Merge remote-tracking branch 'sf_booktype/2.0' into undoplugin
Merge branch 'master' into undoplugin

age aborts