uftpd v1.9

Bug fix release. FTP and TFTP sessions can now run fully in parallel, independent of each other. Also improved compatibility with Firefox built-in FTP client and wget.

Changes

• Upgrade to libuEv v1.2.1+ for improved error handling and a much
  cleaner API.
• Major refactor of both FTP and TFTP servers to use libuEv better.
• Move to use libite v1.0.0 for strlcpy(), strlcat(), pidfile()
  and more.
• Add proper session timout to TFTP, like what FTP already has.
• Add support for NLST FTP command, needed for multiple get operations.
  This fixes issue #2, thanks to @oz123 on GitHub for pointing this out!
• Add support for FEAT and HELP FTP commands used by some clients.

Fixes

• Fix issue #3: do not sleep 2 sec before exiting. Simply forward the
  SIGTERM to any FTP/TFTP session in progress, yield the CPU to let
  the child sessions handle the signal, and then exit. Much quicker!
• Fix issue #4: due to an ordering bug between the main process calling
  daemon() and sig_init(), we never got the SIGCHILD to be able to
  reap any exiting FTP/TFTP sessions. This resulted in zombies(!) when
  not being called as uftpd -n
• Fix issue #5: LIST and NLST ignores path argument sent by client.
• Fix issue #6: FTP clients not detecting session timeout. Caused by
  uftpd not performing a proper shutdown() on the client socket(s)
  before close().
• Fix problem with libuEv not being properly cleaned on distclean.
• Fix problem with uftpd not exiting client session properly when client
  simply closes the connection.