implemented respeaking with on ear playing. Need to consider programmatic volume changes and check that the audio files are segmented correctly for interleaved playing.
fixed bug whereby respeak and pause buttons would become visible after the respeaking is finished because of the proximity detector
added programmatic maximum volume for respeaking in order to prevent the feedback bug (done for the cheap huawei phones, the value may be needed to be lowered for other devices)
Merge branch 'ear-respeak' into phatmerge