Merge pull request #2668 from paul-scott/plotkwargs

plot functions now pass on kwargs when constructing series.
More efficient dispersion computation not using resultants
Docstrings for dispersion functions
Clean up generator handling
Define maximum of empty set
Add tests
Avoid factoring the same polynomial twice
Fix mathematical description
More and better tests for dispersion computation
An even better implementation of the dispersion algorithm
Add Avichal Dayal to AUTHORS/aboutus. Welcome to SymPy!
Add Paul Scott to AUTHORS/aboutus. Welcome to SymPy!
edit simplify_logic docstring
Add complete references
indent discussion of parameters
Trailing spaces removed
Fix a bug and factor over the correct domain
Construct test polys directly
Merge pull request #2698 from smichr/edit

edit simplify_logic docstring
Merge pull request #2699 from smichr/auth

add authors