Implementation of the JSLint tool for ReviewBot. Parses all uploaded files to a review request and outputs descriptive comments on the relevant .js source files on lines where style errors are found. Options for this tool can be configured in the tool's admin panel. This addition to ReviewBot requires that SpiderMonkey be installed (other engines might also be suitable but have not been tested) to enable the running of the jslint.js linting tool.

manual testing:
- tested jslint on the spidermonkey commandline to make sure that the script itself was working as expected locally.
- tested what error output the jslint.com website provides for a given file and tested ReviewBot on local dev server tool by posting a review with same file and ensuring output is the same with the same options ticked (seeing that file with errors was being commented by ReviewBot).
- started by importing all of the dependencies used by the jslint.com website and removed all which were not necessary to the standalone jslint tool, testing that it yielded the same results. Those other dependencies were only necessary for web purposes, even if Doug Crockford suggests they be bundled with jslint itself and minified.
- tested changing options in the option panel, and making sure they affect the output of the static analysis tool in locally published reviews. Included print statements in py and js scripts to make sure the correct options were being passed into jslint.