added/enhanched ref_points near cholet

added reference points for cholet city

changed code so that we can concatenate one or more ref_points files to ref_points.local.php

added grue titan refpoint + untabified that file

Merge branch 'faimaison-specific' of code.rhizome-fai.net:panorama-ttnn into jocelyn-master

and even better with php tags

better with a comma

added first set of points for Nantes

added altitudes of buildings (estimated to ref_points)

added reference points for Rhizome/Compiègne

- Moved ref_points.php to something less toulouse-specific ;-)
by default : no ref points, but the ability to define its own list
or to use one of the files from ref_points folder.
- Fixed the UI if the ref_points list is empty.