Blender Git Loki

cleanup: ortho grid drawing

Getting this ready for Gawain treatment.

Removed setlinestyle(0) -- solid lines are the default, hope this isn't
really needed.

Eliminated redundant math.

Arithmetic is still double precision, passed to OpenGL as single
precision. Even though it said GL_DOUBLE before, values were converted
to GL_FLOAT internally.

Use C99-isms for declaring variables close to where they're used.

Minor whitespace tweaks.