flixel tpl and flixel create fail with misleading error in directories that require admin rights

[Gama11]

See HaxeFlixel/flixel#1435.

If possible, we could show a more helpful error message here (Something like "Template could not be created - admin rights required").

[Gama11]

For some reason Sys.getCwd() returns C:\HaxeToolkit\haxe\lib\flixel-tools\git/ when calling the run.n via haxelib if the cwd is actually C:\...