Better docs for Wild, improved tests for excluded
expanded docs, as suggested
revisions for @smichr

- restore matching tests but without exclude options
- fix ,'s
- docstring revisions so doctest passes
requested changes
fix pep 335 ref and typo in sympy.Pow doc
Merge pull request #2636 from zanzibar7/bug_Wild_exclude_tests

Better docs for Wild, improved tests for excluded