Fixed the problematic leading '/' added automatically by the File class on Android when loading Armatures.
Work on SurfaceExecutorService, allow to use actors with OpenGL surfaces.

- Moved it in new package org.sofa.opengl.akka.
- Moved application.conf in src/main/resources so that it is copied
automatically when building in target.
- Removed the need for application.conf, using
SurfaceExecutorService.configure in static context before the
configuration loads.
- Updated references to SurfaceExecutorService.
- Moved Armature and SVGArmatureLoader in new package
org.sofa.opengl.armature.
- Moved Libraries in package org.sofa.opengl.