Merge pull request #281 from jlaura/network

Snow data and network
- adding example data from geodanet
Merge pull request #282 from sjsrey/network

adding example data from geodanet
testing wed on geodanet/streets.shp
correcting api for wed
api correction
- testing on geodatnet/streets
- adding diagonal option to kernel weights in user.py
Merge pull request #285 from sjsrey/diag

- adding diagonal option to kernel weights in user.py
Merge pull request #284 from sjsrey/network

Testing wed on geodanet/streets example
Merge branch 'network' of github.com:pysal/pysal into network
Merge branch 'master' of github.com:pysal/pysal into network

-adding changes to diag for spatial weights and hac
Merge pull request #286 from sjsrey/network

Network merging master changes into network to keep the latter up to date
- notebook to illustrate how to identify different cases for filament
  insertion
Merge pull request #293 from sjsrey/network

- notebook to illustrate how to identify different cases for filament insertion
Issue 291 Tentative Fix