Add basic tests for the `./mocha` module

I know the name clashing is ugly, but I don't think it's worth changing.
Fix assorted minor bugs and add `JSDOCTEST_DISABLE`

This fixes:
- Running jsdoctest's own tests with mocha
- Running jsdoctest over comments without names
- A typo in `jsdoctest/mocha.loadDoctests`
Add code-coverage support and set-up travis
Add the badge magic dance and bump to 1.1.1