Layered Restructure Proposal

[Brian Molnar]

I'd like to propose some changes to the GTFS specification to open up
some flexibility and create a clearer organization of the data. Such
changes would certainly prove valuable in my application of the data,
but I'd like to see what the thoughts here are.

Unfortunately these changes highly break backward compatibility, but
perhaps this could be considered for a future major revision of the
specification, or some subset of these changes could be implemented in
the existing specification while maintaining compatibility.

http://docs.google.com/View?id=dfxqkb5z_47586gff3

Cheers,
- Brian