Fixed Haxe3 + FLixel 2.55 imports

[Eiyeron]

Hello.

Using directly the library show some import errors with Flixel 255 and Haxe 3. THe imports are wrong and needed to be fixed to make LevelTools work.

I just replaced these line:

import flixel.{subpackage}.{class};

Into these:

import org.flixel.{class};

Have a nice day.