output fence breach type
when switching mode without a fence action do not go into manual recovery
only recover if there is a fence action
implement auto-takeoff fence options
output user-friendly fence names
auto-enable fences on auto-takeoff
use fence enable_configured()
simplify message printing

…ng climb rate

call appropriate fence method for auto-enablement

…ed on the stack

zero out passed in buffers for ExpandingString

avoid fence breach clearing spam

…ecks

control copter floor fence with autoenable
autoenable floor fence with a margin
check for manual recovery only after having checked the fences
make auto-disabling for minimum altitude fence an option
output message when fence floor auto-enabled
re-use fence floor auto-enable/disable from plane
auto-disable on landing
do not update enable parameter when controlling through mavlink
make sure get_enabled_fences() actually returns enabled fences.
make current fences enabled internal state rather than persistent
implement auto options correctly and on copter
add fence names utility
use ExpandingString for constructing fence names
correctly check whether fences are enabled or not and disable min alt for landing in all auto modes
add enable_configured() for use by mavlink and rc
add events for all fence types
make sure that auto fences are no longer candidates after manual updates
add fence debug
make sure rc switch is the ultimate authority on fences
reset auto mask when enabling or disabling fencing
ensure auto-enable on arming works as intended
simplify printing fence notices
reset autofences when auot-enablement is changed

correct detection of polyfence

skip breach checks if no fences
correct initialisation of _num_fences in the case of no fences in eeprom

…ming

clean-up fence manipulation functions and add test for auto-enablement on copter
update tests to have some FENCE_ENABLE tests
add avoidance minimum and maximum altitude fence
add fence switch test while flying
add FenceAutoEnableDisableSwitch for auto mode 2
add more scenarios for plane fence auto-enable
validate fence rc switch behaviour
check fence autoenable by taking off in guided mode
more FENCE_AUTOENABLE tests
add FenceEnableDisableAux and FenceMinAltAutoEnableAbort

…ding is aborted

…k rather than using a state machine

simplify takeoff auto-enablement

…ather than using a state machine

…rather than using a state machine

allow precise pre-arm messages

add Plane.FenceMinAltEnableAutoland
test that vehicle can be landed manually after descending below fence floor

needs to auto-enable on takeoff complete

when we are disarmed or we are not in fence breach and we are not
flying then reset the previous mode fence reason state so that a new
flight will get the correct fence breach action behaviour

the is an adjustment to the previous fix which only worked when we had
at least one fence element enabled when we were not flying or disarmed

when the user has chosen to disallow mode change during fence breach
it should be fully implemented, without a landing exception.

as requested by Pete, and discussed on dev call