Merge branch 'master' into feature/search

Conflicts:
	sql/version-010.sql
	src/client/folder-list/folder-list-folder-entry.vala
	src/engine/rfc822/rfc822-message.vala

Also, I had to manually fix some compile errors introduced due to
interfaces changing on master.

sql/version-012.sql

@@ -0,0 +1,7 @@
+--
+-- Add the internaldate column as a time_t value so we can sort on it.
+--
+
+ALTER TABLE MessageTable ADD COLUMN internaldate_time_t INTEGER;
+
+CREATE INDEX MessageTableInternalDateTimeTIndex ON MessageTable(internaldate_time_t);