Working according to position log

There is still an occasional graphical glitch with the toolpath preview,
but it doesn't seem to affect the machine position.
Added depth output and removed redundant field
Fixed some slowdowns when switching between tangent and parabolic blends
Trying more aggressive parabolic blending again
Debug output for optimization
Added optimization to addcircle but this didn't cure the dips
Fixed the optimization issue finally because the optimization was being run before the new segment was added
Fix for spindle atspeed hiccup
Fix for tangent arc issue that sam found
Preparations for acceleration-dependent tangent epsilon:
Merge remote-tracking branch 'robell/circular-blend-arc-alpha' into ubc3-circular-blend-arc-alpha

Conflicts:
	src/rtapi/sim_common.h
Scratchwork for ini file parameters
Possible fix for overrun due to spinup?
Fixed speed overrun due to at-speed 2 moves ahead
Fix for acceleration violation due to tangent-parabolic transition
Fixed blend velocity calculation to properly estimate parabolic vs. tangent velocity
incorporated Sam's cycle time measurement XML
Merge branch 'hotfix/acceleration-violations' into circular-blend-arc-alpha
Documentation and spacing update
Documentation for tc.c