Optimized and rescaled header image plus pics of Kenneth and Peter

This shaves 555 KB off the front page size.
Merge pull request #26 from Tenzer/image-optimizations

Image optimizations
Fix wrong variable reference on front page
Rescheduled to the 18th and added venue
Typo
Update Rakefile and _config.yml to not throw errors when running jekyll
Also build before starting server
Added january 2014 meetup blog post
Typos
Update lanyrd url
Added speaker suggestion form to the upcoming meetups page
Fixed bug in iframe containment
Update 2013-11-28-december-meetup.md
Update 2013-11-28-december-meetup.md
Update 2013-11-19-november-meetup.md
Added february meetup blog post
Update 2014-01-23-february-meetup.md
Update 2014-01-23-february-meetup.md
Added Iconfinder as drinks sponsor
Added Front-Treds ticket raffle