Link Manager: Add prototype method for ‘remove link by id’
Comms Config: Fixes buttons in dialog showing connect/disconnect correctly

- Clean up commented out code from previous version
Map Widget: Make sure the Waypoint is fully constructed before firing waypointEditableChanged
Waypoint Widget: support spline waypoints

- delegate navigation between waypoints to WaypointNavigation.h
Mission Widget: Add spline waypoint
Waypoint Widget: refactor large methods from WaypointNavigation.h to WaypointNavigation.cc
Map Widget: delete existing waypoint lines when switching to new UAS
Waypoint Widget: Fix Naming on Spline Waypoint
Advanced Param View: added default .param extension

new parameters files were created without .param unless user typed it in,
making files invisible in load/compare dialog
Full Param View: Fix #463, uninitialized state of a boolean causing the param file list to sometimes not download
ParamManager: Fixes #459, segfault due to params not being recieved by the time the UI is done loading