UP-3763:  Allow header/footer portlets to render in the mUniversality theme
UP-3763:  Fix mobile structure XSLT (mobile-column.xsl) so that it doesn't display header/footer portlets marked as 'hideInMobile'
UP-3763:  Now that we've fixed the non-appearance of header/footer portlets in mUniversality, choose 'hideInMobile=true' for our existing header/footer portlets because they're not ready