overhaul frontpage jumbotron, add js for twitter buttons back in, fix up some form ids and classes, straighten out the use of primary button variable

lib/forms.less

@@ -133,10 +133,16 @@ input[type=image] {
   .box-shadow(none);
 }
 
+// Make textarea height behave
 textarea {
   height: auto;
 }
 
+// Hidden inputs
+input[type=hidden] {
+  display: none;
+}
+
 
 
 // CHECKBOXES & RADIOS