Added traffic_sources as array text field to store the project traffic sources as the new form allow multiple choice. Migrated old texts from how_know field (terrible naming).
Adding display_traffic_sources to project decorator to show array of traffic sources as string separated by comma
removed all references to the old how_know field
removed other references in views and i18n to old know_how field
Merge pull request #784 from diogob/bootstrap

Bootstrap fixing new project form