Merge pull request #431 from parkerd/master

add sponsor, close cfp for atlanta 2013
Added proposal from speaker 17
corrected platinum sponsors label
little typo
launching Portland
Merge pull request #433 from agoddard/portland

launching Portland!
Merge pull request #432 from agoddard/master

little typo
fixed link to original image
Merge pull request #434 from agoddard/portland

fixed link to original image
yet another pesky platinum tag
added proposals from speaker 18
Ignite from Speaker 19
a morbid proposal from Speaker 20
Opscode sponsorship
Sponsor logos size
move Demonware from "Gold" sponsor to "Evening"
Vancouver-2013: add silver sponsor Polyglot Conference
Vancouver-2013: Add call for proposals end date
Merge pull request #435 from philwhln/master

Vancouver-2013: Update to sponsors.
Added a stackato logo from activestate.

Changed a couple of "ww" to "www" in links.  It seems like it works
either way for 2u, but not for activestate and saltstack.