Improve Texture class

[G2Pavon]

• Improve texture lock method.

• Add justify tools (first need Read WAD3 files #2)

[G2Pavon]

Texture lock explained by Captain P:

One way to look at texture projection is that you have a texture plane, and you're projecting vertices onto that plane to get UV coordinates. Here is how I apply 'texture fit' when transforming a brush: https://github.com/pwitvoet/mess/blob/master/MESS/Macros/MappingExtensions.cs#L61
I first project a vertex onto the texture plane to get the original UV coordinates (not normalized, so texture size doesn't matter), then I transform the vertices and rotate/scale the UV axis, and then I project the same (now transformed) vertex again onto the now rotated and scaled texture plane to get new UV coordinates. I then use the difference between the old and new UV coordinates to update the UV offset.