Fixes a warning in the compound controller.
Implemented a callback mechanism for the activity controller. Any
additional control elements should be added to the compound control in
similar fashion.
Hooks the viewmodel into the compound controller's callback mechanism.
Adds some documentation as well as an onPause callback to the
controller.
Makes the play/pause button a check button.
Made some more colors constants.
Makes the button change its icon depending on its state.
Removed an unused activity.
Renamed the interval activity to something more normal sounding
("interact" is not a descriptive enough verb).
Adds a custom progress bar which displays progress in a circular path.
Most of the implementation is done except for the colors, which may
require custom attributes.
Puts two progress bars on top of each other.