Return to the Stage viewport when the frame buffer ends.
Drawing resources are translated when resize happens.
Improved shader program performance.
Merge pull request #324 from RotaruDan/framebufferViewportFix

Return to the Stage viewport when the frame buffer ends.
MeshHelper now uses stage coordinates.
This simplifies the drawing by avoiding unnecessary conversions.
Improved Javadocs.
Added automatic saving in Mockup.
Merge pull request #327 from RotaruDan/framebufferViewportFix

MeshHelper now uses stage coordinates.
Merge pull request #329 from RotaruDan/savingSystem

Added automatic saving in Mockup.