SmoothProgressBar: update to v0.4.0

Changelogs:

Added a progressStart() and progressStop() methods
Added parameter progressStart_activated which makes the drawable to animate progressively at each start
Added speed parameters for progressStart and progressStop
Added possibility to set a background for the progressiveStart/Stop (See Pocket example)
Added possibility to set a generated background according to the bars colors
Added a listener progressiveStopEndedListener: called when the progressiveStop animation is over

thanks castorflex