Dasherize all file names
Merge pull request #501 from MajorBreakfast/master

Dasherize all file names
Fix test loader for dasherized file names.

Commit 036df2e2c00aee broke the test loader so that no test modules were
found or loaded, and no tests run.
Merge pull request #504 from alisdair/master

Fix test loader for dasherized file names.