add two finger swipe gesture
use two finger swipe gesture to return to original page in flipping mode
remove unnecessary require
Merge pull request #14 from chrox/swipe_to_return

use two finger swipe gesture to return to original page in flipping mode
add two_finger_pan_release gesture & some refactorings in tap state
Merge pull request #16 from chrox/more_gestures

add two_finger_pan_release gesture & some refactorings in tap state
Merge pull request #19 from houqp/houqp-master

add more instructions for emulation mode