Removing mode buttons in favour of a segmented control

 - auto/rtl buttons removed
 - segmented control added to support Follow Me mode
 - removed defunct background image used for RTL button
Introduced FollowMePointAnnotation

- refactoring to allow dispatch on different point classes
Temporary UI pre-work for testing Follow Me functionality

- temporary sliders (to be replaced by some nice future control; c.f.
iGCS-27) which control bearing/distance/height
- basic calcs to compute new location from current user location using
bearing/distance/height offsets
- display current "follow me" position on the map
Send "follow me" updates periodically, based on GPS accuracy etc

 - reflect heartbeat mode changes via UI controls
Enable GOTO command
disableFollowMeMode
Update UI state to reflect likely autopilot status
Display accuracy of user location
Refine control layout

 - still hoping this is temporary, but can't deal with the ugly
anymore! :-)
Update stale UI elements when switching between guided modes
Pulse the guided mode annotations
Separated active vs requested guided locations

 - will make it simpler to display and reason between the current
GUIDED position (be it GOTO or FOLLOWME) vs the requested (but possibly
not yet sent) follow me position
Rename files to reflect current purpose
Once shown, keep showing the proposed follow position on UI

 - until disabled by a GOTO or mode change
Added labels to temporary sliders
Switch to using user location
Merge branch 'master' into follow-me

Conflicts resolved in:
	iGCS/UserInterface/MainStoryboard.storyboard
	iGCS/UserInterface/ViewControllers/GCSMapViewController.m
Merge pull request #8 from cnatoli/follow-me

First cut at "Follow me" functionality