Ensure <util.h> is included so that its implementation of fparseln() can compile.

This adds compat code for fgetln/fparseln and conditionally includes libutil.h where required. This is needed at the moment for mailcap, but might be useful for other things in the future.

libevent is a very cool library, I like the APIs and enjoy using it. However, telescope is not as large and doesn't have as many file descriptor, so libevent is quite ``too big'' for our needs. ev started as a small event loop on top of poll(2) for amused, and can be used here too, it just needed to grow the ability to handle several timers, as we need quite some on telescope (in fact, we use more timers than fds!)

Splitting stuff into sub-directories was just a big mistake.