AP_HAL_Empty: added register_io_process()
AP_HAL: added AP_HAL_PX4 define
autotest: make default param files end in .parm

this matches what MP wants in its compare params diaglog
AP_Compass: fixed ARM 32 bit compatibility
AP_Param: Fix compiler warning on Flymaple
Plane: workaround conflicts between wirish and APM compatibility
AP_HAL: changed base defines for print()

this avoids a conflict with wirish from libmaple
Plane: fixed build with print() base change
Copter: make compat functions static

this prevents conflicts with libmaple
Rover: make compat functions static
Rover: fixed build with print() changes
AP_OpticalFlow: fixed build with print() API change
Copter: removed logging of MAVLink parameter changes

not much point to this
Rover: removed SLIDE_SWITCH and PUSHBUTTON defines

not used anywhere
Copter: removed CONFIG_PUSHBUTTON

not used anywhere any more
Update GIT_Success.txt

Added my name to the list... just testing
AP_InertialSensor: prevent a lockup in MPU6000 driver

thanks to the VRBrain port for noticing this bug.

Failing to get the semaphore is an expected error with the MPU6000, as
we read data both from timer context and mainline code. That means
semaphore conflicts are inevitable. We shouldn't consider them an
error, and shouldn't panic when some arbitrary number of them have
happened since boot.

Instead the wait_for_sample() code checks that we receive new data at
least every 50ms. That is a much safer test.
APM_Control: make the default time constant 0.75

thanks to Tom for the testing!
Rover: make the default period 8

thanks Tom!
Rover: create 2.43beta5