add bubble images
add illustrator file for bubble images
add bubble animation code
incorporate bubble animation into view controller
change bubble intensity with volume
change bubble intensity in response to up/down/mute
make screen width a property for the bubble object
handle device rotation
set maximum bubble size based on screen width
add retina images
parameter adjustment
Merge branch 'develop' of https://github.com/KomodoOpenLab/VolOver into iss7
Merge pull request #8 from tnantais/iss7

Fixes #7