Performance enhancements to mostly MachineCom, ~2x performance

I've gathered up a bunch of my local commits to improve the performance of the send routines of MachineCom. These combined enhancements cut the execution time spent just about in half. Tests were performed on a 12,000 line gcode file sent through the Virtual printer driver while profiling the MachineCom thread. Baseline 2min 13sec, result 1min 5sec (Raspberry Pi 700MHz).

The functionality should be identical, however I removed the com logQueue. I'm not sure what this was used for but keeping it consistent was 18% of cpu time. The gcode handlers (matchesGCode()) were also moved to parse the GCode type once then call a class method named after the parsed gcode. This was a relatively minor speed improvement, but it definitely reads a lot easier.