FlxTilemap#loadMap(): support Array<Array<Int>> instead of Array<Int>, closes #1290
Merge branch 'dev' into tilemapLoadMap2Darray

Conflicts:
	flixel/system/FlxAssets.hx
Split loadMap() into csv, array and 2d array versions
Merge branch 'dev' into tilemapLoadMap2Darray

Conflicts:
	flixel/tile/FlxBaseTilemap.hx
Fix merge conflicts
No need for casting anymore
Merge pull request #1292 from Gama11/tilemapLoadMap2Darray

FlxTilemap#loadMap(): support Array<Array<Int>> instead of Array<Int>, closes #1290, closes #1324