Adds View->Voxel Edges to toggle voxel edge display, closes #21.
Fix: Correct save ambient occlusion display setting.
Fix: Fill tool could cause crash, closes #23.

Trying to fill voxels with a colour when they already were that colour would cause a crash.
Can hold down mouse button and drag with paint tool, closes #22
Changes to the DrawingTool, where it can now draw lines when the left mouse button is dragged
Solving issue #26, now with the possibility of adding multiple grids to the scene.
Fixed issue #29 - Grid resizing
Strip all trailing whitespace, fixes #31
Merge branch 'develop' of git://github.com/brunocanella/zoxel into brunocanella-develop
Changes to the DrawingTool, where it can now draw lines when the left mouse button is dragged
Merge branch 'brunocanella-develop' into develop
Fixes OBJ file exporter, closes #30
Insection works for all grid planes, closes #28
Fix grid insection checking from last commit.
Tones down default grid colours, closes #39.
Remove "auto-resizing" feature for model dimensions.

Let's assume models are always of known dimensions.
Axis floor grid to axis grids, closes #40
Don't auto detect model size on file open, use saved model dimensions, closes #41, closes #37
Remember model dimensions as use as defaults, closes #38
Delay before detecting drag, closes #42