Impove image viewing

[cemachelen]

button pressing between hours is clunky. Javascript up-down arrows or jump to might be better

mark suggests odometer style

[cemachelen]

Minor Improvements

1. Set nav bar text colour to black
2. Set sensor tab as sensor map OR
   Preview set up of map with a click for current data plots like on sara's web page!
   (if sensors ever get turned back on then ready for Live data!)
3. Add GitHub link to footer

[cemachelen]

MAJOR

Plot as layers using MARTIN TOOL