[Mobile] IN PROGRESS: Styling in forms, overlay and tree

open #74
.section-header and form-row styles changed in forms/_elems.scss;
significant changes to overlay in mobile: full-screen, close button, more;
tree hover bg changed to use rgba(#fff, 0.1);
removed "Hide title by default" in core/bundle.json;

platform/core/bundle.json

@@ -117,12 +117,6 @@
                         "pattern": "\\S+",
                         "required": true,
                         "cssclass": "l-med"
-                    },
-                    {
-                        "control": "checkbox",
-                        "name": "Display title by default",
-                        "key": "displayTitle",
-                        "property": [ "display", "title" ]
                     }
                 ]
             },