We currently implement our own versions of these on mingw because that platform doesn't have them... but why reinvent the wheel; libevent has already done the same thing. Let's use libevent2's implementation.
has already done it for us.
This commit adds a set of package-visible structs and functions to allow delegating announces and scrapes to different protocol handlers. (Examples: struct tr_announce_request, struct tr_announce_response, struct tr_scrape_request, struct tr_scrape_response.) HTTP is the only protocol handler currently implemented; however, this provides a clean API for other protocol handlers, and having this in trunk will help shake out any bugs in this refactoring.
In addition, logging via the TR_DEBUG_FD environment variable is vastly improved in the announcer module now.
