Only animate on re-layout
Enable flash plugin for SoundJS.
Note that there seems to be something with my MP3:s that make them
unplayable by Internet Explorer. The "reward" sounds play fine also in
Windows Media Player, but the letter sounds do not.
Lower z-index when animating removed stimuli
We also need to register HTMLAudioPlugin.
Add WebAudioPlugin also since it seems recommended, although I'm
not sure what the benifits are compared to just using HTMLAudioPlugin.
Merge branch 'master' of github.com:skagedal/folksy