Cleanup fix, mainly removing get-injectable

Added a summaryoutput object for zone and parcel output in order to get rid of get injectable in that part of the code - probably has bugs at this point.

Also adding extensive doc strings and moving a few functions into injectables in datasources.py.

More to come, but I want to move this to the server for testing.
forgot to cache the summary output object

also srid should have been epsg

also turned the networks into an injectable rather than a model so you don't have to remember to cache the results
removing egregious use of injectables
Merge branch 'remove-get-injectable' of https://github.com/synthicity/urbansim_defaults into remove-get-injectable
don't clear the injectables cache

some of these objects persist year over year and so should not be cleared
all the utils functions should have doc strings now

yeah!
Merge branch 'remove-get-injectable' of https://github.com/synthicity/urbansim_defaults into remove-get-injectable
moved full transition model to utils.py

this allows sharing of code between the household and jobs transition models, which were basically the same
basic sphinx docs are now generated from the docstrings
the same changes I made in sanfran_urbansim

updating to fix warnings that come up in pandas .15
Merge pull request #3 from synthicity/remove-get-injectable

Remove get injectable