Connected component subgraphs copy

Add option to copy (or not) subgraph data.
Rework connected components algorithms as generators.
Add example for sorting components by size
Merge pull request #1006 from hagberg/master

Force ordering in dict_to_numpy_array functions
Drop official Python3.1 support

But pretty much everything will work OK.  Some small issues with xml.etree are annoying to support specially for Python3.1.
Merge pull request #1007 from hagberg/drop-python3.1-support

Drop official Python3.1 support
Clean up the mess I left in #1006

Remove a print statement and some commented out code.
Remove @require decorator
change the other code in networkx/algorithms/components to return generators of components instead of lists of components, Add option to copy (or not) component subgraph data.
Use list() with component generators

Update to strongly connected component algorithm to return generator requries explicit use of list() in simple_cycles()
Whitespace and formatting cleanup
Avoid use of list() in condensation
Merge pull request #1 from hagberg/francis-liberty-issue_973_generators_copy

hagberg added some fixes:
Fix cycles algorithm by adding list()
Clean whitespace and formatting
Rework condensation to avoid use of list()
Merge pull request #1009 from francis-liberty/issue_973_generators_copy

change the other code in algorithms/components to return generators instead of list, Add option to copy (or not) component subgraph data.
Merge pull request #973 from hagberg/connected-generators

Connected component subgraphs copy
Merge pull request #1008 from hagberg/no-require

Remove @require decorator
Fix shebang line for platform independency
Merge pull request #1014 from xmj/master

Fix shebang line for platform independency