Bug 849426: Port /about/history.html to bedrock

- new pages created on wiki with old content of some pages:
  - www.mozilla.org/about/bookmarks.html ->
           https://wiki.mozilla.org/Historical_Documents
  - www.mozilla.org/about/timeline.html ->
           https://wiki.mozilla.org/Timeline
- new /about/history/ page on bedrock with existing content from
  old /about/history.html, and links to new wiki pages

We should also establish redirections from the old pages on
www.mozilla.org:

  www.mozilla.org/about/history.html -> new /about/history/
  the two pages moved to the wiki listed above