Add more tests to PatternTestCase.  The first two fail with the
current code.
Fix minor bugs in IncludePattern and ExcludePattern, and speed up
ExcludePattern by storing a compiled regular expression.
Add one more test to PatternTestCase.
Simplify IncludePattern and add a few more tests to PatternTestCase.
Simplify the ExcludePattern logic further, and explain.
Fix a doc typo.
Merge pull request #33 from jdchristensen/exclude

fix include/exclude bugs and add more tests