Add initial sponsors

Puppet Labs
Chef
ModCloth
Univerity of Pittsburgh
Merge pull request #673 from littleidea/pittsburgh

Add initial sponsors
[ljubljana 2014] add media sponsors
[ljubljana 2014] resize sponsor logos
Merge pull request #674 from extraordinaire/master

[ljubljana 2014] media sponsors & resize logos
[ljubljana 2014] replace netokracija logo
Merge pull request #675 from extraordinaire/master

[ljubljana 2014] replace netokracija logo