Merge branch 'master' into dev
removed Dropifi
added helpers for URL inputs, fixed form alerts, specified required fields, minified some css files
Merge branch 'responsive'
Merge branch 'master' of heroku.com:peaceful-woodland-7453
grouped required fields
Merge branch 'master' of https://github.com/devcongress/devcongress.com into dev
Merge branch 'dev'
added Register and Agenda links
changed text of register on nav bar
added sponsors on about page, refactored about us, text.