Mission planner

[yashdeep97]

Contains the following changes:

• Allow user to clear geofence and set current geofence when starting the drawGeofence mode. Partial fix for [UI] fea. Allow modification of geofence #34
• add methods for abort, go home and stationkeeping. Fix WebUI: add standard mission commands #8
• Allow user to delete mission points. Partial fix for [UI] Add mission planner #13
• Toggle display mission points on pressing view button/selecting in mission planner. Fix WebUI: Simplify mission view control  #10.
• MapUI: Allow inserting point between 2 other points if they are collinear. Fix fea. Add ways to insert point between missionPt and geofence points #33