Universal diff reporter, proof of concept.

Add a reporter which produces universal diff output, for easily resolved errors. Currently only handles missing semicolon errors. Does not produce any diff context, but does handle multiple changes on a single line. Assuming the output has been piped to <patchfile> its output can be applied (after modification if required) by running gnu patch like so, "patch -p0 -i <patchfile>". Which will patch multiple files, and fix missing semicolon issues.

issue #859
https://github.com/jshint/jshint/issues/859