[Enhancement] Mobile support

[pepf]

I currently listening to fusic from my mobile phone (using a "stay awake") widget from the play store.
This works fine, however it would be nice to accomodate for this in the interface:

• bigger buttons (especially play/pause)
• fixed player on the bottom of the screen (not zoomable)
• Improved search/add dialog, perhaps also fix it on top of the screen? (only on mobile)