Implemented unittest_file_glob, pyfix_unittest_glob, and
integratedtest_file_glob.  Fleshed out tests for *_file_glob, refactored
to make a bit more DRY.

This implementation is intended to be completely backwards compatible
with 0.10.2, including at the function level in case any third parties
are directly invoking the underlying implementation.  There are three
new properties:

1. integrationtest_file_glob
1. pyfix_unittest_file_glob
1. unittest_file_glob

If a project sets one of the previous *_file_suffix properties, that
will override the matching *_file_glob property and log a warning that
*_file_suffix has been depricated.

At the implementation level, there are new functions that have "_method"
concatinated to the original function names: discover_files_matching,
discover_modules_matching, execute_tests_matching,
discover_integration_tests_matching.

The oringal function names that expect a suffix are still present and
functional but have been refactored to leverage the underlying
"_matching" function.
Fixed failing tests, ensured reverse compatibility.
Fixed discover_modules_matching() to only match python source files regardless of the file_glob.
PEP 8 compliance. Doh!
discover_modules_matching() adds '.py' to glob if needed, only matches '.py' files.
Renamed unittest_file_glob and pyfix_unittest_file_glob properties to the more correct unittest_module_glob and pyfix_unittest_module_glob. The final .py is no longer required (but OK if present). The integrationtest_file_glob property was left as is, since the integration tests really do run files (where as unittests import modules.)
Merge pull request #55 from markmevans/file_glob_feature

Implemented unittest_file_glob, pyfix_unittest_glob, and integratedtest_file_glob. Fleshed out tests for *_fileglob, refactored to make a bit more DRY.