Fix bug 844914 - MWC link cleanup

* External links open in new tab/window
* Updated WIPJam link
* Updated mozorg home page news
Fix bug 844915 - update MWC demos schedule
Fix bug 844969 - MWC cleanup and presentation tweaks
Fix bug 845389 - copy change in page intro
Merge pull request #648 from craigcook/mwc-cleanup

MWC cleanup