Bringing Accept header parsing in line with the spec.

For reference:
  http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.1
  http://www.w3.org/Protocols/rfc2616/rfc2616-sec2.html#sec2.2
Ensuring that generated Content-Type headers properly escape params.
Exposing Accept header parameters.
Simplifying regular expression to silence warnings.
Explicitly set falsy values for :template should not render a template
chat example: .live is removed in latest jquery, use .submit
convert README.ru.rdoc to README.ru.md
fix code blocks in README.ru.md
Default host to localhost when in development mode.

* Running Rack apps on 0.0.0.0 in development mode will allow malicious
  users on the local network (ex: Coffee Shop) to abuse or potentially
  exploit the app. Safer to default host to localhost when in development
  mode.
Update README.jp.rdoc
typos in README.ru.md
Merge pull request #635 from akicho8/patch-1

Update README.jp.rdoc
Merge pull request #636 from vast/readme-ru-md

Convert README.ru.rdoc to markdown
README: Clarify what the special `not_found` and `error` handlers do
Merge pull request #637 from cypher/issue-610

README: Clarify what the special `not_found` and `error` handlers do
chat example: use .on instead of submit
Merge pull request #634 from postmodern/localhost_development

Default host to localhost when in development mode.
don't run rdiscount tests on 1.9.2
Merge branch 'master' of github.com:sinatra/sinatra
lock to rdoc 1.x for now