Merge pull request #256 from Livefyre/rc

RC -> Master (content source type mixins) :rocket:
Revert build-css script
2.12.1
Compile css
Assign authorUrl to authorAvatarUrl if not defined.
Bump patch ver to 2.12.2
Merge pull request #265 from Livefyre/authorUrlFix

Author url fix
Modals can have opts.parentNode passed on construction. 2.12.3
Compiled css
StateToContent accepts a state with author object
Bump ver to 2.12.4
Merge pull request #266 from Livefyre/bs31

StateToContent supports bootstrap 3.1-style attachments & author obj on content
Fix bottom margin for featured label on content view
Handle featured annotation stream and re-render body view.
Bump patch ver to 2.12.5
Merge pull request #267 from Livefyre/featured

Featured stream fix
Fix regression in 2.12 for ie hack where LivefyreContentViews need to detach their buttons before setting innerHTML to nothing
2.12.6
Merge pull request #270 from Livefyre/fixIe9BugFix

Fix ie9 bug fix
FeaturedContents now has a FeaturedUpdater. FeaturedContents itself is now a Readable