[conf] fixedwing ahrs use gps course instead of mag for heading by default
[ahrs] warn if PERIODIC_FREQUENCY is lower than AHRS freqs
[config] better warning message and update example airframe
[stabilization] Float euler bounding and scaling fix
- added BoundAbs to properly bound the commands
- removed gain denominators in the control loop (i.e. now the gains should be more consistent with other stabilization systems)

First, it is easier to set your gains now, as the values set by GCS/airframe config are the ones actually used (no division).
Second, the gains are in the same range as for other stabilization systems (no need to change xml settings files for GCS to get proper range).
[plotter] open new plotter with parent settings
[plot] draw curves at low resolution when moving/selecting in log plotter

much faster when dealing with huge logs
[stabilization] fixed MAX_SUM_ERR
[boards] add driver for KroozSD BigRotorcraftEdition

- IMU with memsic MXR9500 accelerometer
- set mag correct freq to 75Hz for krooz_sd_x

closes #586
[build] ARM toolchain/Makefile cleanup

- possible to explicitly pass a PREFIX to use other toolchain
  default for PREFIX is arm-none-eabi or arm-linux-gnueabi
- print meaninfull error if arm-linux toolchain is not found
- printcommands prints only CC and GCC version
- remove obsolete find OpenOCD stuff
[types] add support for new telemetry types

Comming from the old 'messages' branch:
- support for char and 64 bytes
- support for fixed length arrays
[convert] support for ARCH_ALIGN_INT64
[rotorcraft] fix some attitude ref telemety message sending
[PPRZ CENTER] Added some more verbose io watch callbacks.

Trying to investigate the issue of immediately closing processes in
paparazzi center on mac os x Mountain Lion and Mavericks.
[PPRZ CENTER] Different approach for io_watch signal handling.

This time we have only one watch reacting to OUT and HUP, wheras it is
ignoring OUT signal and running callback only for HUP.
[PPRZ CENTER] Capture more of the IO signals.

Trying to gather a bit more data on the signal behavior.
[PPRZ CENTER] Fixed detection of child processes exitting on Mac OS.

We are now checking if the input channel is empty when receiving the IN
callback. If that is the case we assume that the child process exitted,
ond call the close process callback that normally is treggered by the
HUP callback.

Some background: On OS X glib is using it's own implementation of poll
that does not generate the HUP signal. (It would be possible to add this
functionality modelled after the SSH implementation of bsd_poll) The
glib implementation does generate IN signal when the pipe get's closed.
So we can just check if the input channel is empty and if that is the
case infer that the pipe got closed.
Merge pull request #588 from podhrmic/master

[stabilization] Float euler bounding and scaling fix

you need to divide the old dd-gain by 512 and the old i-gain by 1024.
Merge pull request #592 from esden/pprz_center_osx_fix

Paparazzi Center on Mac OS X: fixes #290

The missing HUP signal was found in the simulated poll function in glib. The glib implementation is copied from glibc which does not implement HUP but only generates an IN event instead (Mac OS default behavior would be to generate HUP & IN events together). The solution I went for was to just check if the channel is empty on IN event, and call the HUP callback.
[conf] cleanup some trailing whitespaces
[messages] add char, fixed size array and int64 support to transports and gen_messages.ml