Fixed a bug with timing of injecting regex replacements
moved T (extruder) tracking to queued command stream
check that we have loaded filament on extruder 1
issue: MatterHackers/MCCentral#5029
Don't do actual switch of extruders until there is a pending move command
Only build a movement string for the values we know the position of
initialize unknown positions to Unknown (rather than Zero)
Added get to check for fully known position
issue: MatterHackers/MCCentral#4681
Export making M114 assumptions about Z
