Added support for JavaScript-style comments in JSON files and improved t...

JSON does not allow for comments... Maintaining our configuration files, which are starting to get gigantic, is therefore quickly becoming a nightmare! This PR allows for comments in JSON files in Mojito by stripping those files from JavaScript-style comments before passing them to JSON.parse. Also, this PR improves a bit the situation with JSLint, although I noticed JSLint does not like the intentional fallthrough in the switch statement... I like it, personally. We can revisit that later if it turns out to be a problem...

This is a new PR following PR #796 which was made from the develop-perf branch which went away... @lzhan confirmed in a private email that this PR was indeed needed because it seems that files with a .json extension are not parsed by the YAML parser (which may not even support JSON)