[build] remove 'load' target from makefile

It is a special command in Make 4.0
update create_module helper
code style formaters

fix_code_style.sh script uses astyle which works very well.
Eclipse is not very good at this, but better than nothing...
[flight_plan] set primitive should not delay next stage

when a set is called, it should not stop the navigation for 1/4 second.
[flight_plan] fix return primitive
[release] v5.2.1 stable version
Merge branch 'v5.2' of https://github.com/paparazzi/paparazzi into proto2