NPC-380 #comment Fix left-nav height overflow problem. Left nav no longer
sticky, but not a big loss.
Merge pull request #274 from brev/npc-380-website-left-nav-fix

NPC-380 #comment Fix left-nav height overflow problem. Left nav no longe...
Adding contributor
Adding YHAck NuPIC slides.
Merge pull request #276 from rhyolight/add-yhack-slides

Adding YHAck NuPIC slides.
Merge remote-tracking branch 'upstream/gh-pages' into gh-pages