Extend SwipeHelper to support vertical gestures
* Un-hardcode CONSTRAIN_SWIPE and FADE_OUT_DURING_SWIPE, define
  through proper callback, per-layout
* Up (GESTURE_NEGATIVE) and down (GESTURE_POSITIVE), mostly needed
  by new Hover hide /w swipe up gesture

- @cristianomatos: minor adaptations to fit crDroid sources and heads up

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>
Change-Id: I68c42a8ccabca73a1b241ba7cf264db9c912fccd

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java
HOVER: Implement hide only on swipe up

    * Add an Y axis HideHelper, just extend current X axis SwipeHelper and
      change interested methods behaviors
    * Some clean up and indenting

    Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>
    Change-Id: I42a260ea993c614b0b9b4558a95dd44dd517c4f1

Change-Id: I9d699ac0a6e632bc1110e93cac9d924611525014