Clean up flashing code

Hasty commits from the wilderness are bad plans!
See and Buy Powerups for #5
backport to v2.7

Allow use of AchievementList property
Earn Kisses for #6

Earn 1 for each unlocked Achievement.
Flash kiss symbol #6

Each time an Achievement is earned, flash the icon to a kiss symbol.
Purchase decks for kisses, closes #6
Currencies on ActionBar

... and reorder to fit and overflow correctly.
Save settings off-site, fixes #33

(I hope...)
Refactor win screen
Display Powerups for use, #5
Use Powerups, closes #5, closes #32
Merge remote-tracking branch 'origin/powerups'

Conflicts:
	gui/screens/game.py
	main.py
	rendezvous.kv
Merge remote-tracking branch 'origin/master' into debugging

Conflicts:
	gui/components.py