console: Console window now closes when module is unloaded.
map: Map window now closes when module is unloaded.
mavproxy: Now catches Ctrl-C and requires 'exit' to quit.
mavproxy: requireexit setting added.  Ctrl-C only caught if set.
mavproxy: automatically restore console and map after Ctrl-C
modules: removed unusued module methods
only call unload if module has unload attribute
console: fixed packet reporting
keep vehicle_name attribute

used in paramater download and diff
mp_util: added download_files()
param: background download, and improved diff
mp_settings: fixed settings that start as None
rline: allow other modules to complete on commands
HIL: reversals can now be done with plane RC params
cameraview module to draw a polygon showing fov.

Assumes the terrain is all flat in the field of view.

Stabilisation-corrected code is untested and likely to be quite wrong.

Stole a couple of functions from mavproxy.py, which should probably be
moved somewhere else for the sake of cleanliness...
mavflightview: support EKF position viewing
param: make "param set NAME" show a parameter

makes for faster interaction for show then set
fence: now using MAV_SYS_STATUS_GEOFENCE to track fence state.
fence: can now enable/disable fence from GCS.
fence: now outputs color-coded fence status to console status