Bunch of changes:  minor bugfixes, tile test additions, fixed checkbox default text color glitch
updated flixel-ui with latest changes from flixel. Will probably need further polishing, this gets my project to compile, and I dont notice any issues.
Small changes - created an "addAsset()" function and various other sundries.
Added data/definition consolidation and deprecated "9slicesprite" tag, use "chrome" instead, or "nine_slice_sprite"
Added FlxUIDropDownMenu - only works in code for now, will add xml loading logic later.
Minor tweak
Fixed velocity in FlxUIGroup
Merge remote-tracking branch 'gltovar/dev' into dev

Conflicts:
	flixel/addons/ui/FlxUI.hx
	flixel/addons/ui/FlxUITabMenu.hx
Fixing up flixel-ui for upcoming flixel release
safety check for FlxUIButton
Fixed some logic errors in button loading w/ regard to 9-slice-scaling. Now throws error if you provide only one asset but no src_w/src_h.  XML loading is unchanged - it now deduces the proper src_w/src_h values for an "all" tagged graphic asset.
Added basic icon support to FlxUIButton.

Using these methods:

addIcon( icon:FlxSprite )
removeIcon()
changeIcon(newIcon:FlxSprite)
removing isStatic constructor argument for text classes
Fixed to bring in line with Sam's changes to flixel
Fixed issue where UI wasn't shown. Removed inline keyword from FlxUIGroup.calcBounds (bad use of inline).
Merge branch 'master' of https://github.com/HaxeFlixel/flixel-ui
Fixed bug which made checkboxes and radio buttons in a tab menu all clicked by default.
Fixed some (but not all) neko bugs
Making FlxUIPopup compatible with latest dev version of flixel.
Merge remote-tracking branch 'origin/master' into dev