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
When the user leaves text hanging, complete the tag

The tags product depends on one of the `confirmKeys` to be pressed. This change
simply does the same thing if the text field is blurred.
Clean up some serious ugliness.
Restore the blue arrow on table insertion.
Merge pull request #136 from oerpub/video-plugin-new

first pass on media embed plugin (issue - https://github.com/oerpub/Aloha-Editor/issues/132)
Merge pull request #142 from oerpub/salvage-tag-on-save

When the user leaves text hanging, complete the tag on blur
Merge pull request #143 from oerpub/recover-blue-arrow-for-tables

Recover blue indicator arrow for tables
Add back arrow for image insertion
Merge remote-tracking branch 'origin/master' into undoredo

Conflicts:
	src/plugins/oer/semanticblock/lib/semanticblock-plugin.coffee
	src/plugins/oer/semanticblock/lib/semanticblock-plugin.js
Move the blue arrow handling to semantic block module

The class to which the css is glued, is handled by the semantic block module,
and all semantic blocks that use the insertPlaceholder and
insertOverPlaceholder machinery will get it for free.
Changes to keep better track of placeholder.

* insertPlaceholder now returns the jquery object of the inserted placeholder.

* no more magic cleanup of old placeholders that may be left behind, plugins
  should clean after themselves.

* insertOverPlaceholder now requires that the placeholder be passed to it.
  Explicit is better than implicit.

* Changes to figure, image and media plugins to accomodate the above.