Android: Integrating wave form branch! PeakFileService now supports non-floating point decoding channels. The WaveFormView control now displays the status of generating a peak file. WaveFormCacheManager is based on the same class on iOS; all that's left to do is to actually draw the waveform in a bitmap in another thread. But generating a peak file and loading it afterwards works and does not slow down the UI or the player so far. An interface/abstract should be added later to WaveFormCacheManager to centralize as much code as possible.

Related to issue #406.