Investigate use of clang-format for style enforcement

As discussed in #55, Closure Library uses clang-format to enforce style conventions and formatting in their project, since Closure Compiler linter.jar does not really do much in the way of formatting. It might be nice if Closure Rules was able to incorporate this.

Why is this important? Because Google's JavaScript and Closure style guides are by far the most difficult and onerous. Far more complicated than C++, Java, or Python style. Especially if you're used to the anarchy of non-Google JavaScript development, where style is shunned entirely in favor of succinctness. So I imagine newcomers would be rather shell-shocked by Google's style conventions at first introduction. It would be fabulous if a tool could help them.

I personally do not have the cycles to take this on. Right now I'm focused on making the features that we have, work as advertised. If others could investigate this further, it would be awesome.

CC: @hochhaus (since it won't allow me to assign directly to you)