vimeo cell now extends iframe cell
added sticky field (iframe and vimeo cells); only the last clicked iframe or vimeo will be active, unless its sticky field is set to true
limited focusing to iframe and vimeo cells (only one can be active at a time, except sticky ones)
sticky field (iframe/vimeo cell) also allows '1' instead of 'true'
added 'loop' and 'autoplay' fields to vimeo cell

resolves #30 #25
Revert "added 'loop' and 'autoplay' fields to vimeo cell"

This reverts commit d23dbaa077e6aca138d272bc3fa0463645c42ab0.
added 'loop' and 'autoplay' fields to vimeo cell

resolves issues #30 and #25
added 'loop' and 'autoplay' fields to vimeo cell

resolves #30 and #25
added "activate!" and "deactivate!" messages for sticky iframe cells (via postmessenger)

#15
Merge pull request #31 from martinleopold/master

Updates to issues #15, #25, #30