Add new module for flow based connectivity and cut algorithms
Fix doctests and python twoisms for the new connectivity module
Add Robins and Alexander bipartite clustering
Add new clustering functions to the documentation, plus some small docstring improvements
Merge pull request #771 from jtorrents/bipartite-clustering

Add Robins and Alexander bipartite clustering
Fix header spacing for development docs.
Add spacing in pdf download links.
Merge pull request #813 from hagberg/doc-fix

Doc fixes
modified grid_graph generator to not mutate input parameters
Merge pull request #814 from AndrewWalker/master

More Pythonic behaviour for the grid_graph generator
Merge pull request #742 from jtorrents/connectivity

Add new module for flow based connectivity and cut algorithms
Add force scaling parameter to spring layout.

Add parameter k to specify optimal distance betweneen nodes in spring layout.
The default is 1/sqrt(number of nodes).
Rescale layout on every step to be in [0,1] box.
Remove spurious print and empty notes field.
Add faster tests for graphical sequences.

Use linear time algorithm.
Add testing for directed, multigraphic, and pseudographic sequences.
Whitespace cleanup.
Change canonical name to is_graphical from is_valid_degree_sequence.
Small doc formatting fixes and updates.
Combine basic graphical setup into single function.
Change graphicality testing function names

Use is_digraphical(), is_pseudographical(), and is_multigraphical().
Add graphicality testing docs