Improve release_notes view to fix multiple bugs

    Improve release_notes view to fix multiple bugs
    
    Map URLs within bedrock for bug 978931
    
    Map firefox os release notes urls to new RNA powered release_notes
    view, with fallback to manual templates for 1.0.1, 1.1, and 1.2 to
    support the template development for bug 978988
  
    respect Release.is_public flag unless settings.DEV is True for Bug 980055  
    
    Map auroranotes to RNA release_notes view
    
    Beta notes will also work if the version # matches the version_re,
    which for example 28.0b1 will, but 28.0beta will not
    
    We no longer "fix" version numbers like 27.0 -> 27.0.0 for Bug 974667-- this was
    an artifact of data migrations that we need to fix in the nucleus
    DB now that we've gotten past those migrations
    
    mobile release notes are not yet supported, further work
    will be done as part of Bug 965012.