Add Conical ESS Turnpoint for PG optimized Task.
fix Conical ESS Task point drawing
avoid wrong config for Conical ESS turnpoint
allow Cone base altitude less than 0m
replace Radius by Slope for Conical ESS turnpoint in task Overview dialog
Do not print "Message" in the airspace warning dialog. We know it is a message, for sure.
	modified:   ../Data/Dialogs/dlgLKAirspaceWarning.xml
	modified:   ../Data/Dialogs/dlgLKAirspaceWarning_L.xml
Move engineering option airspace message repeat time back to airspace warning params.
This is used for the case we set a low timeout time and we dont want the message to be repeated every 5 minutes.
set airspace message repeat readonly if warnings are disabled
Merge branch 'ConicalESS' of https://github.com/brunotl/LK8000 into conical

Conflicts:
	Common/Header/Task.h
Adjust Task Overview turnpoint list item layout
update changes
more diagnostic for DEBUG_STOP_RXTHREAD
Fix logger problem when lat or long minutes are exactly 0 sharp in W or S .
Appearing as negative N or E , instead of positive S or W.
There is no "negative" lat or long, because we use S and W for the scope.
Update credits
fix wrong error message claiming the filesystem is not writable while the system folder is just missing.
fix McCready Speed calculation :
  wrong max speed to integer convertion and wrong exit loop condition

before this change, McSpeed max value is "absolute value of MaxSpeed (in m/s)" - 1m/s

it's critical bug for paragliders : error > 10% of max speed (3.6km/h to 7.8km/h)

TODO : use less speed step for MC Speed, for now we use 1m/s (3.6km/h)
  it's to huge for paraglider, common PG wing have only 10 to 15 km/h speed range.
Update changes
eng_msg update
This is version 4.1f
Advance to next beta