Implement edit user modal

EditUserHandler is a bit rough

less/forum/app.less

@@ -7,6 +7,7 @@
 @import "DiscussionList.less";
 @import "DiscussionListItem.less";
 @import "DiscussionPage.less";
+@import "EditUserModal.less";
 @import "Hero.less";
 @import "IndexPage.less";
 @import "LogInModal.less";