Added AccelerometerMotion functionality

Maybe changing directions a bit to include more features that may be needed.

Signed-off-by: Bradley Baysinger <bradley@seven2.com>
Minor

Signed-off-by: Bradley Baysinger <bradley@seven2.com>
Wired up various Playback classes to watch System.hidden, and pause while in the background.

Signed-off-by: Kipp Ashford <kipp@seven2.net>
Remember if the Playback was already paused when hiding.

Signed-off-by: Kipp Ashford <kipp@seven2.net>
Fix to pause sounds when iOS device is locked or when Safari goes into the background.

Signed-off-by: Kipp Ashford <kipp@seven2.net>
Merge pull request #114 from volkipp/pause_sound_bg

Playback classes now wired to watch System.hidden, and pause while in the background
Minor tweaks.
Return the right prefix for unprefixed APIs.

Fixes System.hidden in the latest Firefox (and other browsers with an
unprefixed Page Visibility API).
Prevent all calls to update() while hidden.

Some browsers (Firefox) seem to call the requestAnimationFrame callback
once even when hidden. That was causing sounds to sometimes not unpause
correctly when coming back from hidden.
Merge pull request #113 from braddelcat/accelerometer

Accelerometer for HTML
NotifyingSignal1 is generally useful, hoist it up into flambe.platform.

Also renamed it to HeavySignal1, it might get extra features later.
It sounds like FlashAccelerometer isn't ready yet, disable for now.
Always initialize the orientationUpdate signal.

It's handy to be able to stick a listener on orientationUpdate without
explicitly having to check orientationSupported (touch and keyboard
signals are like this too).
Accelerometer documentation and cleanup.
Update hasListenersValue after an emit.

hasListeners() while dispatching may return the wrong value (disconnects
are deferred until the end of the current dispatch).
Lazily construct Accelerometer, so it gets dead code eliminated.

(In Haxe 3)
Lazily init Keyboard too.
Remove components from a previous entity, without disposing.
Nape 2.0.9 won't install, use 2.0.8.

Refs deltaluca/nape#60.
Partial merge branch 'master' of https://github.com/aduros/flambe into accelerometer

Altered to be consistent with changes from Bruno. Added some comments.

Signed-off-by: Bradley Baysinger <bradley@seven2.com>

Conflicts:
	src/flambe/input/Accelerometer.hx
	src/flambe/input/AccelerometerOrientation.hx
	src/flambe/platform/flash/FlashAccelerometer.hx
	src/flambe/platform/html/HtmlAccelerometer.hx