Remove unnecessary uv var from makeVines_.  Fix up vine rendering by rotating the texture in drawVineTexture_ so that the uv coordinates passed to the vertices on the top of the vine match the top of the actual texture (or where the top is supposed to be, at least).  Could also rotate the uv coordinates around, but if the original code was confusingly rotating the texture around (by -pi/2), might as well keep it doing that (just by +pi/2 this time).  Possible bug in the original frontier code.