Nicer defaults for server, connector, and handlers

Tweaks some of the defaults to be a bit nicer. The core changes are as follows:

* GZip supprt for various text response MIME types.
* Instrumented external handler for more metrics.
* Capped and instrumented default thread pool.
* Removal of server HTTP headers that pose a "security" issue
* Allow rapid restarts with socket reuse
* Grace period during shutdown to give requets a chance to complete
* Use X-Forwarded-For header for remote IP