Fixes in Media player service and Pomodoro timer

Added the possibility to set an initial offset for audio playback
fragments. When this is set, these fragments will start from the
desired point in the audio file.

Also did some UI fixes in Pomodoro fragment, to make the look a bit
more flat.
Merge branch 'development' of https://github.com/henke101/Mindy into development

Conflicts:
	res/drawable/drawer_item_pressed.xml