Transparent tab colour adopted

 - modified the waypoint editing screen to have a black background (so
the transparent tab bar has a consistent colour across all screens)
 - adjusted waypoint editing status bar button padding slightly, per
previous feedback
Tone down follow me controls with alpha = 0.85

 - storyboard thumbTickColor didn’t appear to be respected (at least in
the sim)
Set application-wide tint colour
ThemeManagerSingleton introduced
Corrected storyboard warning
Renamed singleton instance accessor for consistency
Merge pull request #35 from fightingwalrus/igcs-79-tab-color

Igcs 79 tab color