add keyboard and devicemotion to entropy.
keypress for ie8.
Merge remote-tracking branch 'origin/master' into feature/entropy_motion_keyboard
Merge remote-tracking branch 'origin/master' into feature/entropy_motion_keyboard
addCurrentTimeEntropy for all event listener.
keypress add time to prevent side-channel attacks.
Merge remote-tracking branch 'origin/master' into feature/entropy_motion_keyboard

Conflicts:
	core/random.js
Merge pull request #119 from bitwiseshiftleft/feature/entropy_motion_keyboard

add keyboard and devicemotion to entropy.