Merge pull request #1 from lyuma/fix2018

Compile fix for unity 2018

Fix distance biases and add option for atlas compression

- Fix distance biases because some colors of text could still turn into quads at a distance.
- Add option to compress font atlas with BC7 compression if people really care about the extra few MB of VRAM.
- Change _TextColor param on test mesh shader to _Color to match the normal shader.
- Add support for text color to the text mesh shader

Add examples