Initial pass at a MNLLocationChoiceModelGroup class.
Initial pass at a SegmentedMNLLocationChoiceModel class.
Add YAML IO methods for SegmentedMNLLocationChoiceModel.
Merge branch 'master' into lcm-group
fixes to get semented lcm to work

Added some changes to yamlmodelrunner, tested for estimation_sample_size larger than choosers, a bug when the "name" is set to 0, and a few other small things
pep8 issue
Merge pull request #33 from synthicity/lcm-group

This is now performing segmented lcms for semcog for both households and employment.  Appears to be working quite well after a few changes were made.
Merge branch 'master' into regression-debug

Conflicts:
	urbansim/models/yamlmodelrunner.py