FlxPoint support for log and watch / log security

- added FlxPoint support for log and watch
- added formatFlxPoint() helper function to FlxU
- added security feature to Log.hx to avoid inserting html tags
Log: html tag security improvement

Didn't account for arrays that contain html tags previously
Better logging documentation and more

- Improved documentation for the new logging functions in FlxG a ton.
Especially important since they could be confusing due to showing up as
fields in auto-comletion (FD at least)
- Added formatHash() to FlxU
- Improved help command once more
- fixed bug where FlxG.advancedLog()'s Data param had to be an Array or
would cause an error otherwise
Merge pull request #377 from Gama11/texture_point

FlxPoint support for log and watch / log security
update to 2.0.0-alpha.2
fix for FLX_MOUSE_ADVANCED
Made functions in FlxMath Float-compatible
Merge pull request #390 from Gama11/dev_FlxMath

Made functions in FlxMath Float-compatible
Fix for negative object width and height
fix for last changes of FlxPath and FlxObject
Added Frame parameter for FlxSprite's play()
forgot about check for no-negativity
added randomize functionality for play()
Merge branch 'dev' of https://github.com/HaxeFlixel/engine into dev_FlxSprite
gotoAndPlay, gotoAndStop, pauseAnimation and resumeAnimation methods
FlxAnim frameRate
Slightly better frameRate, sorry for spamming
Merge pull request #393 from Gama11/dev_FlxSprite

Fix for negative object width and height
fix for camera's scrollrect on html5
fix for FlxSprite's randomFrame() and for issue #397