cpplint: make lint rules closer to node's source

* Support C-style header guards (/* comments */)
* Support `class NODE_EXTERN something`
* Support `}  // extern "C"` closures
* Ignore header order
* Ignore `long/short` usage (because of OpenSSL's API)
src: lint c++ code
make: add `cpplint` to `test` target

Also, exclude some C-headers, machine generated headers and tweaked
sources from cpplint file list.