fix yahoo/mojito-cli-jslint#6 exclusions too loose

- change from .json to .js and use real regexes
- use anchored regexes to avoid sub-string matching.
  i.e. so "docs" doesn't exclude "docs.js"
- move patterns from `always` into app/mojit/mojito. this
  enables usage without a type to be more general. user
  can supply own --exclude params.
if type is specified but no source, assume cad
Merge pull request #8 from isao/issue6

fix yahoo/mojito-cli-jslint#6 exclusions too loose