codestyle: specify line-ending, trailing-whitespace and tab rules

# This file provide reference settings for the APM code conventions
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# respect the conventions contained within this file.
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Copter: add V-Tail to FRAME param's @Value
Copter: fixup line endings to be newline
Tools: fixup line endings
Tools Serial Proxy: fixup line endings
AutoTest: fixup line endings
AC_PID: fixup line endings
AP_ADC: fixup line endings
AP_Airspeed: fixup line endings
BattMon: fixup line endings
Compass: fixup line endings
Notify: fixup line endings
OptFlow: fixup line endings
AP_Param: fixup line endings
PID: fixup line endings
Copter: Document stream rate parameter functionality
AC_Circle: add get_closest_point_on_circle

init_start_angle method added to use current heading or position to
decide on initial start angle
Copter: integrate change in AC_Circle init

Removed init_loiter_target when vehicle landed.  We should add some
initialisation of the circle controller when landed.
Copter: Loiter_Turns moves to edge of circle if location provided
Copter: remove unused circle_desired_rotations

desired num rotations is already held in command so we save 1byte of RAM