Support --reporter and --reporter-output when running tests.

When running any Grunt task that runs tests with Mocha, the two
following command line options are now supported:
- --reporter: allows to specify a reporter, default is 'spec'.
- --reporter-output: allows to specify a file where Mocha's output will
  be stored.

These two command line options make it easier to retrieve and parse test
results when tests are run on a continuous integration platform like
Jenkins.

Fixes #4038.
Merge pull request #4039 from misterdjules/output-tests-results-to-files

Add option to specify reporter and output file via grunt.
Add jscs task to grunt file and clean up files to adhere to jscs rules.

resolves #1920

- updates all files to conform to style settings.
Merge pull request #4001 from hswolff/jscs

Add jscs task to grunt file and clean up files to adhere to jscs rules
Cleanup reserved words in generateSlug

closes #1889
- Adds a new filter for slugs
- Move slugs to config.slugs