Added better error checking when opening files in
create_gtfs_from_basicinfo.py, and also added routes to GTFS in sorted order
of name.
Just cleaning up comments.
Work so far on stop creation algorithm. Tested that it works for:-
 * Start and end of route stops
 * Transfers within self
 * Transfer points to train network.

Has various parameters based on distance to try to avoid too many stops close
together etc.

Created a separate file as part of this for geometric projections onto lines,
as this was adapted from internet sources.