Merge pull request #985 from simplysoft/flexible-frontendjs-compilation

More flexible frontend.js compilation
Merge pull request #987 from simplysoft/flexible-frontendjs-compilation

recompile frontend.js with updated plugins
fix race condition in screen refresh

- add dispose method fields
- check for null position in all connection callbacks

fixes #988
update frontend.js
update rails configs
Merge pull request #989 from simplysoft/flexible-frontendjs-compilation

Improve check for closure library installation
Merge pull request #990 from simplysoft/fix-988

Fix race conditions in screen refresh
add space after breaks
treat marquee as ticker content
Merge pull request #991 from concerto/marquee_tweaks

Marquee tweaks
Replace a few is_admin? checks with can? calls, close #976.
use correct cache when templates change