Fix #103 using 'all' as a default target

#

# TARGETS

# -------

.DEFAULT_GOAL := all

all:	gui do_all 

	@echo " . . . 'all' done" 

clean : clean_all 

	@echo " . . . clean done"

	@rm calibrationtool_ui.py

	@rm calibrationtool_ui.py*

clean_dist : clean_all clean_dist_all 

	@echo " . . . clean_dist done"