Set up node-jscs, pass it, and configure in local Gruntfile

Let's experiment with this via our local Gruntfile. If it works
fine we can install it in Jenkins (similar to node-csslint).

Verify through $ npm install && npm test;

Fixed all outstanding violations.

Also:
* Added syntaxhighight to ignore.
* Added imetests (which contain unformatted JSON) to ignore.
* In ve.dm.ModelRegistry#matchTypeRegExps, removed redundant
  !! cast from the [+!!withFunc] statement which was hitting
  a bug in node-jscs. All callers to this local private function
  pass a literal boolean true/false so no need to cast it.
* Removed "/* key .. , value */" from ve.setProp, though this
  wasn't caught by node-jscs, found it when searching for " , ".
* Made npm.devDependencies fixed instead of using tilde-ranges.
  This too often leads to strange bugs or sudden changes. Fixed
  them at the version they were currently ranging to.

Bug: 54218
Change-Id: Ib2630806f3946874c8b01e58cf171df83a28da29