Refactor LabelValuePair into a class

typedefs compile into Dynamics on cpp
Pool LabelValuePair
Refractored NumTween and FlxTween.num()
Accept an option object and tweenFunction
FlxAngle: make TO_DEG and TO_RAD (get, never) so they can be inlined
Borrow workaround for numpad and function keys not working on native targets from @HaxePunk, openfl/openfl-native#193
FlxKeyboard: fix NUMPADPERIOD correction, add NUMPADMULTIPLY
CachedGraphics: use FLX_RENDER_TILE
Use FLX_RENDER_TILE in calcFrame()
Compile fixes for FLX_RENDER_TILE on flash
Inline FlxKeyboard.resolveKeyCode()
Adding functionality to set a single camera that an FlxBasic object will be drawn to.
Merge branch 'dev' of https://github.com/HaxeFlixel/flixel into dev
NumTween: Recommend the usage of Function.bind
FlxKeyList: add missing NUMPADMULTIPLY, use spaces for formatting
Add FlxPoint.weak() and putWeak()
Make FlxPoints in FlxSwipe and FlxTypedEmitter (default, null)
Merge pull request #920 from kevinresol/numtween_refractor

Refractored NumTween and FlxTween.num() (Closes #914)
Small change for the description of FlxTween.num() + style cleanup
Abstract FlxPointHelper into FlxCallbackPoint
FlxTilemap: replace scaleX and scaleY with a scale FlxPoint to be consistent with FlxSprite, #814