Introduced spindle status structure

* Implemented spindle status structure to encapsulate state variables used
in tpRunCycle.
* Partially refactored spindle-synchronized motion based on new
structures.
* Minor cleanup of previous refactoring to be more compact and useful.
Minor fixes in prep for demo
Fixed error codes but still hanging at G61
Kludge fix of tc pointer bug
Removed unneeded tcqItem argument

Quick debug infrastructure

Further debug flags towards rigid tapping, not working still
Moved debug macros to separate header
Refactored spindle sync position and velocity mode.

Tested changes in simulation with simple rigid tap cycle. No obvious
errors at this point.
TODO: exhaustive tests with multiple moves
TODO: velocity mode tests.
Organized simple ngc tests into folder
added missing header
Merge branch 'feature/synchronized-motion-refactor' into develop
Removed stray tabs and refactored enqueueing function in preparation for optimization routines
slight tweak to test code to demonstrate overshoot glitch when we lose a segment
Added ignore entry for cscope