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
mavproxy_tracker: prevent error if map module not loaded
mavproxy_tracker: support new command 'tracker param set NAME VALUE'
mavproxy_tracker: support new command 'tracker mode <manual|auto>'
mavproxy_tracker: Added support for 'tracker position BEARING PITCH' command
fence: added enable/disable to completions
tracker: fixed completions
Use a more current documentation link: http://tridge.github.io/MAVProxy/
devel: Install a dumpstacks handler on SIGQUIT

If you send QUIT to Mavproxy it will dump stack traces on all threads.
modules: added mp_module class

this will be the new template class for all modules
refactor core code for new module structure
modules: refactor modules for new structure
module: fixed vehicle_name, say and logdir
antenna: fixed mavlink_packet()
arm: fixed throttle arming
console: fixed link delay calculation
fence: fixed fence logdir and display