persistant expanded notification with play/pause/stop buttons
add settings options for  persistent and expanded notifications
disable expanded notification option when unsupported & provide informative toast
use persistant notification option for persistant lockscreen controls
Merge branch 'notifymore' of git://github.com/mchelen/AntennaPod into mchelen-notifymore2
Replaced numbers with constants
Changed preference label

Preference affects both lockscreen and notification.
Merge branch 'mchelen-notifymore2' into develop
Updated changelog
Lock in PSMP was not properly released