MDL-43723 remove draggable headers from blocks when blocks are displayed on the entire window width

    This patch mainly remove the phone problem with users dragging a block around when instead users want to scroll down/up the screen.
    It does not resolve the issue on touchable device with large screens. These screens need serious thoughts as users are likely
    to encounter the same issue BUT sometimes users do want to drag blocks from right to left / left to right.