Baro_Glitch: initial version of baro glitch protection

Based on GPS Glitch protection library
Notify: add baro_glitch flag
InertialNav: skip baro updates when glitching

Also resets inertial nav alt estimate once glitch clears
INav_EKF: accept baro_glitch in constructor

Required so it can create an InertialNav object
Copter: integrate baro glitch protection
SITL: add ACC_BIAS and BARO_GLITCH parameters

These allow testing accelerometer bias which often comes from vibration
and sudden changes in baro altitude.
HAL_AVR_SITL: integrate ACC_BIAS and BARO_GLITCH

Adjust simulated accelerometer values and barometer altitude
Notify: RGB led flashes yellow-purple for baro warning
Notify: baro warning tone alarm
Notify: APM2 buzzer for arming, ekf and baro failures
BaroGlitch: shorten param prefix to BAROGLTCH_
Copter: log flight mode after arming
InertialNav: fix example sketch
AC_AttControl: fix example sketch
AC_Fence: fix example sketch
AC_Sprayer: fix example sketch
AC_WPNav: fix example sketch
Copter: fixed ESC calibration on Pixhawk

this ensures motors are armed after safety is pressed, and also gives
print out of channel inputs and outputs on USB console for debug
purposes

Pair-Programmed-With: Randy Mackay <rmackay9@yahoo.com>
AP_Math: port examples to Linux
Replay: fix example sketch