Feature/set output pin

A simple method for configuring default pin values for pins that need to be set at startup, but don't need to be modified thereafter.

Example configuration:

set_output_pin.alpha_ms1_pin           10.29!
set_output_pin.alpha_ms2_pin           10.30
set_output_pin.alpha_ms3_pin           10.31!

Would set the stepper motor mode pins for the alpha axis to 0b101 (32 micro-steps).