NavBar re-org

Re-Organized NavBar - added button for home and pushed the menus with
submenus to the last.
MQ changes for Gallery

MQ changes for Gallery page - still not performing well with images
wider than their height.
MQ based adaptable NavBar items

MQ based adaptable appearance for NavBar menus and submenus - reduced
font size, padding and margin for lower resolutions;
No BG for pages less than 770px width.