= Improvements

* The render/view methods in the render plugin, when called with
  a single string/symbol argument (the most common case), are now
  up to 2.5x/4x faster by directly calling compiled template methods.
  This works by extracting the UnboundMethod objects that Tilt
  creates, and defining real methods for them, then calling those
  methods using send. This avoids most of the overhead of the render
  and view methods.  The compiled template methods are defined inside
  a module included in the Roda app's class, so this support works
  even if the Roda app itself is frozen.

  Some plugins, such as render_locals, do not work with this
  optimization, and disable the use of it.  The view_options plugin
  does work with this optimization if you are using set_view_subdir or
  append_view_subdir, but not if using set_view_options or
  set_layout_options.

  This optimization depends on Ruby 2.3+ and Tilt 1.2+, and will not
  be used on earlier versions, or if an API change in Tilt is
  detected.

* Session deserialization is now slightly faster in the sessions
  plugin.
