Fix texture skewing and texture repeats
Closes #4 (closed) and #7 (closed)
Cherry picks 2bbb2aaf30806986c77f45796a7e189efc0f5b2a, fixing the effects of "Slope Skew" and "No Midtexture Skew"/midtexture skewing in visual mode. Visual mode midtexture selection works as expected.
Also fixes texture repeats, displaying them in visual mode. Selection also works as expected.
Edited by frostu8

