Recents panel: Clear all in navigation bar / pie

Revised by C3C0:
- squashed all commits into one
- minor changes regarding formatting
- major glitch fixed - details below

When recents key has no actions set (default for both - single and
long-press) and when user is in recents and long-presses the clear all
key, action is taken, recents screen is dismissed but it is immediately
reopened afterwards when user releases the key - this is because in the
meantime recents key was changed back to normal.
Solution: wait until user releases a key before changing it to normal