festival: Update to the new datatype style

Among some other things, this:
 - Introduces class constants for all tag and attribute names in the
   page XML.
 - Updates process() to the new style, also handling commands there
   instead of using registerCommand.
 - Updates view / command method names to the new style.
 - Makes form generation and handling consistent, using hypha_substitute
   and making more parts translated.
 - Add makeActionButton and constructFullPath helpers (to be generalized
   later).
 - No longer uses global variables.
 - Use variable substitution when generating e-mails.
 - Return 404 where appropriate.
 - Styling is removed from the HTML and moved to the CSS file (except
   for the timetable, which should probably be rewritten anyway).

This also makes some functional changes:
 - Signup and contribution forms now have a default value for when they
   are not specified in the XML (these would have to be manually edited
   in the XML file up until now).
 - E-mails are now stored as translation texts and no longer
   configurable in the page XML, since there was minimal customization
   in practice and this makes things simpler.

This relates to #135 and #335.

Author: matthijskooijman

data/themes/default/hypha.css

@@ -862,6 +862,57 @@ textarea{
 .festivalTimetable .tableRowHeadingEven {
 	background-color:#bbb;
 }
+
+.festivalForm th {
+	text-align: right;
+}
+
+.festivalForm input, .festivalForm select, .festivalForm textarea {
+	width: 400px;
+}
+
+.festivalForm textarea {
+	height: 100px;
+}
+
+.contribution h2 {
+	clear: left;
+}
+
+/* Include #main to override #main img */
+#main .contribution img {
+	float: left;
+	border: 0px;
+	margin-right: 10px;
+}
+
+.contribution .event {
+	clear: left;
+}
+
+.contribution .date {
+	font-weight: bold;
+}
+
+.contribution .time-and-place {
+	margin-left: 1em;
+}
+
+.contribution .website {
+	clear: left;
+}
+
+table.contributions .description,
+table.contributions .notes {
+    padding-left: 50px;
+}
+
+/* Include #main to override #main img */
+#main table.contributions .description img {
+    float: left;
+    margin: 5px 10px 0 0;
+}
+
 body.type_peer_reviewed_article .input-wrapper.field_type_editor:not(.field_name_text) .wym_iframe iframe {
 	height: 150px;
 }