GUI: Use opacity instead of alpha (html/css like).
Add more tire model documentation.
Remove unused (and immediate mode) GRAPHICS_GL2::DrawBox.
Cache selected texture unit, saves about 30% call time per simple single textured object.  GLSTATEMANAGER doesn't take texture unit into account, only enables/disables first unit, should be fixed eventually.
Style: Spelling fix in comment.
Remove unused REDNER_INPUT_SCENE::SelectAppropriateShader and redundant GetCull check.
RENDER_INPUT_SCENE move DrawVertexArray code into a function, move GL_LINE_SMOOTH setup to BeginScene.
Cache tire friction to reduce Tire::getForce calls in the solver loop.
Check for zero response.accumImpulse when calculating tire friction coefficients.
Apply friction limits instead of their extrema in vehicle solver.
Rewrite tire to calculate friction coefficients for the solver, use more descriptive variable name in tire code. Clamp tire slip rate and angle. Move tire state update out of solver loop. The tire state will lag by one simulation step but should be more consistent(calculated from current vehicle state update). Simplify tire squeal factor calculation(empiric). Tested with 360 and 350Z on ruudskogen.
Move ABS/TCS implementation into separate functions. Implement (crude) slip angle based stability control. Bump replay version due to this.
Remove unused angvel variable.
Comment fix.
Remove removed wheel angvel variable initializer...
Take aerodynamic drag and downforce into account for braking distance estimation. Gives better results at higher velocities.
Revert to pre-newsim state.
Add bullet >= 281 support (no fracturing).
Add missing cassert includes.
Delete duplicate tracksurface.h.