= New Features

* A default_status plugin has been added for changing the default
  status for responses.  Previously, the default status was hard
  coded to 200, this plugin allows you to change it.  The plugin
  takes a block which is instance_evaled in the context of the
  response:

    plugin :default_status do
      headers['Content-Type'] == 'foo' ? 201 : 200
    end

  Note that the default status for empty responses (used when no
  route handles the response) is still 404, this just changes the
  default for non-empty responses.

* A response_request plugin has been added for giving the response
  instance access to the related request.  This can be useful in
  conjunction with the default_status plugin, if you want the
  default status of the response to depend on the request, such as
  using a different status for different request methods:

    plugin :response_request
    plugin :default_status do
      request.post? ? 201 : 200
    end

* A run_handler plugin has been added, for modifying rack response
  arrays before returning them when using r.run.  Additionally, it
  allows for continuing with routing if the response returned by
  r.run is a 404 response, using the :not_found=>:pass option:

    plugin :run_handler
    route do |r|
      # Keep running code if RackAppFoo returns a 404 response
      r.run RackAppFoo, :not_found=>:pass

      # Change response status codes before returning.
      r.run(RackAppBar) do |response|
        response[0] = 200 if response[0] == 201
      end
    end

* Roda.rewite_path in the path_rewriter extension now accepts a block
  to allow for dynamic replacements. The block is yielded a MatchData
  instance:

    rewrite_path(/\A\/a/(\w+)/){|match| match[1].capitalize}
    # PATH_INFO '/a/moo' => remaining_path '/a/Moo'

    rewrite_path(/\A\/a/(\w+)/, :path_info => true) do |match|
      match[1].capitalize
    end
    # PATH_INFO '/a/moo' => PATH_INFO '/a/Moo'

* The :host matcher in the header_matchers plugin will now yield the
  regexp captures to the block if given a regexp when the
  :host_matcher_captures application option is set.  This behavior
  will become the default behavior in Roda 3.  This will allow for
  code like:

    opts[:host_matcher_captures] = true
    route do |r|
      r.on :host=>/\A(\w+).example.com\z/ do |subdomain|
        # ...
      end
    end

= Other Improvements

* RodaCache now uses a mutex to synchronize access on MRI.
  Previously, it relied on the global interpreter lock, but testing
  has shown that is not reliable in all cases.  RodaCache has always
  used a mutex for synchronization on other ruby implementations,
  this just extends that code to MRI as well.