Add support for Spotify (squashed commit), and:
    - Try to not return items which a client can't play
    - Remove inotify subscription to IN_MODIFY and IN_CREATE
    - Fix crash on unknown codec type in transcode.c
    - Probably added some new bugs...
README update
Format README table for GitHub
Fix horrible filescanner bug I introduced with the Spotify commit
Repair legacy filescanners (broken by libav conditions)
Another filescanner bug fix after Spotify commit
Let configure check libevent version and include according to version
Use EVBUFFER_EOL_CRLF for evbuffer_readln to make sure that the end of
the rtsp-header (an empty line) is recognized
Adjust INSTALL info for Debian
Make mdns_avahi.c fully compliant with libevent 2, so it doesn't
complain in the logs about missing event base for event_del_
Forgot to remove some debug messages in mdns_avahi.c
Spotify: When track ends, empty buffer before stopping. Also some
safeguards against indefinite waits and null pointer dereferencing.
Reduce Spotify logging a bit
Small logging change
Prevent notify_main_thread from mucking with SPOTIFY_EVENT before an
event has been processed
Oops
Filescanner should not watch for IN_MODIFY
- it is bad for performance (triggers many db selects) and is
useless anyway.
Play only a single item when playspec has item-spec (Podcasts/Audiobooks)
Small DAAP changes to align with iTunes
Rewrite spotify to use libevent for better reliability