Updates media to specific commit on latest dev HEAD.

This eliminates a number of bugs and improves the ability to use
media tokens in ckeditor. The specific commit selected is only
to ensure that there's a static snapshot of the module so that
subsequent dev commits don't silently break our media
implementation.
Merge pull request #3 from kevinchampion/update_media_version

Core: Updates media to specific commit on latest dev HEAD.