Fix NMEFont, rename to AbstractFont
Filter properties should be public
Include SDL2.dll dependency on Windows for now, until static linking is properly working
Remove unneeded SDL2 DLL, now that SDL2 links statically on Windows
Getter functions for Tilesheet

Added getTileCenter, getTileRect and getTileUVs to reflect
openfl.display.Tilesheet.
This necessitates adding haxe arrays for tiles, points and uvs, but
adding tiles is rare and overhead is negligible.
Upside is Tilesheets are far less opaque. Downside is users can shoot
themselves in the foot if they want, or data can potentially desync
between nme and openfl.
flash.system.System conditionals

cpp flag isn't being set by FlashDevelop during code completion requests
so the #if cpp is causing errors
Merge branch 'master' of https://github.com/furusystems/openfl-native