An example of combining the G43.2 compound offset idea with remapping to create
a toolchange similar to Fanuc. 

T1 = select and load tool 1, and apply the base offset for tool 1
T0101 = select and load tool 1 and apply offsets 1 and 10001
T0201 = select and load tool 1 and apply offsets 1 and 10002

This might not exactly match Fanuc, but the behaviour is easy to change
by editing toolchange.ngc