first pass on media embed plugin
copy change on media embed dialog
some small updates to media embed plugin
move help text on media plugin modal
Merge remote-tracking branch 'origin/master' into video-plugin-new

Conflicts:
	src/plugins/oer/semanticblock/lib/semanticblock-plugin.js
Merge remote-tracking branch 'origin/master' into video-plugin-new

Conflicts:
	src/plugins/oer/semanticblock/lib/semanticblock-plugin.js
remove figure logic from images (image metadata broken)
add image metadata back in
fix up media embed plugin to work with new figures
only show figure placeholders on hover
Merge pull request #136 from oerpub/video-plugin-new

first pass on media embed plugin (issue - https://github.com/oerpub/Aloha-Editor/issues/132)