v3.0.0pre1

unicorn 3.0.0pre1

Rewindable "rack.input" may be disabled via the
"rewindable_input false" directive in the configuration file.
This will violate Rack::Lint for Rack 1.x applications, but
can reduce I/O for applications that do not need it.

There are also internal cleanups and enhancements for future
versions of Rainbows!

Eric Wong (11):
      t0012: fix race condition in reload
      enable HTTP keepalive support for all methods
      http_parser: add HttpParser#next? method
      tee_input: switch to simpler API for parsing trailers
      switch versions to 3.0.0pre
      add stream_input class and build tee_input on it
      configurator: enable "rewindable_input" directive
      http_parser: ensure keepalive is disabled when reset
      *_input: make life easier for subclasses/modules
      tee_input: restore read position after #size
      preread_input: no-op for non-rewindable "rack.input"