unicorn 0.5.0

* There is an API change in the {after,before}_fork hooks
  so now the entire Worker struct is exposed to the user.
  This allows Unicorn to unofficially support user/group
  privilege changing.

* The "X-Forwarded-Proto:" header can be set by proxies
  to ensure rack.url_scheme is "https" for SSL-enabled
  sites.

* Small cleanups and tweaks throughout, see shortlog (below)
  or changelog for details.

Eric Wong (32):
      test_helper: redirect_io uses append and sync
      configurator: allow hooks to be passed callable objects
      Add a test for signal recovery
      Documentation updates
      Enforce umask 0000 with UNIX domain sockets
      local.mk: touch files after set-file-times
      Add test for :preload_app config option
      GNUmakefile: remove unnecessary asterisks in output
      GNUmakefile: allow "make V=1 ..." for verbosity
      test_configurator: rename test name that never ran
      cleanup some log messages
      test_request: tests esoteric/rare REQUEST_URIs
      http11: Remove qsort/bsearch code paths
      http11: handle "X-Forwarded-Proto: https"
      close listeners when removing them from our array
      config: handle listener unbind/replace in config file
      README: doc updates
      Restore unlinked UNIX sockets on SIGHUP
      listen backlog, sndbuf, rcvbuf are always changeable
      Remove _all_ non-POSIX socket options
      http11: cleanup+safer rack.url_scheme handling
      test_exec: fix potential races in fd leak test
      test_http_parser: fix broken URL in comment
      Save one fcntl() syscall on every request
      Remove unnecessary sync assignment
      Don't bother restoring ENV or umask across reexec
      old_rails: try harder to ensure valid responses
      small cleanups in signal handling and worker init
      Remove unnecessary local variables in process_client
      Expose worker to {before,after}_fork hooks
      Configurator: add example for user/group switching
      unicorn 0.5.0