Merge branch 'rack-1.5' (cleanup release diff)

* rack-1.5:
  Bump version number
  Add release notes for todays releases
  Prevent symlink path traversals
  Stop overwriting existing pidfiles.
  Use secure_compare for hmac comparison
  Add secure_compare to Rack::Utils
  Ensure binary modes are used in tests, for Windows
  Fix a bug where host matching occurs out of order
  Add JSON cookie coder. To be default after 1.6+
  add license information to gemspec
  Fix reference link
  Document Rack::Deflater
  Request#trusted_proxy? no longer accepts lines
  Add find and set methods to Session object

Conflicts:
	lib/rack/session/cookie.rb
	rack.gemspec
	test/spec_session_cookie.rb