core: proxy support: use X-Forwarded-For header for client address when available
core: remove getPort() method on RestxRequest

This method was not used, and was the only one to provide segmented
 URI info (no sheme or host access). The implementation/response get even
 less clear when using proxy, so it's better to remove it.
core: proxy support: use Via, X-Forwarded-Proto and X-Forwarded-Host headers

This makes using RESTX behind a reverse proxy (especially an Apache one)
and still use request.getBaseUri() to return customer facing URLs much easier.
monitor: fix: access time should not rely on nanoTime which can't be converted to date
core: add 2 new lifecycle events, called with entity routes only

- one when input has been read
- one when output has been returned by endpoint and is about to be written