Q1 Pro Remixed Rear Toolhead Cover and optimized CLEAR_NOZZLE macro

This toolhead cover/CLEAR_NOZZLE macro combination allows the toolhead to center the nozzle over the purge trough instead of being too close to the metal roller. This allows the purged filament to easily escape the metal purge trough and drop into the plastic purge bucket at the rear of the printer. Do NOT use the macro as is unless you have printed and installed the new rear cover. The CLEAR_NOZZLE2 macro is optimized for minimal passes over the rollers and felt, making it much faster than factory. LBRY Tags: q1 pro; clear_nozzle; purge