refs ITC-127: added left chevron image to the img folder for offcanvas button
refs ITC-127: modified the templates to use the new image chevron
refs ITC-127: styled the new chevron image for off canvas buttons
refs ITC-127: removed unnecessary javascript that changed the offcanvas button's class
fixes ITC-127: proper image displays when off-canvas button is active and inactive.  Framework laid for an alt image for active offcanvas button