Extended UI widgets to handle erasing functionality.
Added erasing functionality, also undo/redo correctly working.
Fixed small bug while traslating when resizing.
Fixed Windows path problem while saving the drawing.
Improved drawing algorithm.
Fixed a bug that would cause Templates to copy an existing image into the same folder.
Added exit button in the first view
Merge pull request #347 from RotaruDan/Exit

Added exit button in the first view
Improved erasing process by caching some inputs before uploading to the GPU.
Improved saving drawn images algorithm, now the saved images have Y-UP coordinates.
Merge pull request #334 from RotaruDan/erasingFunctionality

Erasing functionality.