minor navbar css
update SoundManager2 to v297a-20130324
SM2 is now started through player.init(useHtml) which
can be called multiple times with different values of useHtml.
This will allow user settings to enable/disable html5 audio.
Setting useHtml to true by default (for now).
fix TestEdition: can no longer edit 2 songs from different albums in the same request
errors are no longer displayed in a floating popup,
they are now displayed properly on an independent page
fix #56 : contextual actions only displayed when selection not empty