interface enanchement and Line following

[CorradoMotta]

As part of this issue:

• Adding line following functionality
• Enhance interface documentation and elements

[CorradoMotta]

To do:

• Fix menu bar elements and visualization
• Add lat lon on top of markers
• Lat lon ref green marker should replace the "manual" marker when coinciding

[CorradoMotta]

Line following should be tested.

To do:

• fix menu bar elements
• lat lon green marker should be rethought

[CorradoMotta]

All done