FMUv1: Reduce excessive stack sizes
FMUv2: Reduce excessive stack sizes
Merge branch 'master' of github.com:PX4/Firmware into stack_reduce
Merge branch 'master' of github.com:PX4/Firmware into stack_reduce
Merge branch 'master' into stack_reduce
Reduce IO buf space reasonably
Merge pull request #1171 from PX4/stack_reduce

Stack reduce
Merge branch 'master' of github.com:PX4/Firmware into airspeed_test_fix
Merge branch 'airspeed_test_fix' of github.com:PX4/Firmware into airspeed_test_fix