Added option to add canonical link to dektop site.
Added option to add canonical link to dektop site.

Websites with separate URLs for desktop and mobile websites need to have a canonical link on mobile site pointing back to the desktop version for SEO.
More Information: https://developers.google.com/webmasters/smartphone-sites/details#separateurls
globalepub/mobile-boilerplate,Saajan/uber-mobile,filtercake/mobile-boilerplate-timetable-3,wjb12/mobile-boilerplate,h5bp/mobile-boilerplate,filtercake/mobile-boilerplate-timetable-3,wjb12/mobile-boilerplate,Saajan/uber-mobile,cyprianos/bold,xieQin/mobile-boilerplate,COBSNAN/mobile-boilerplate,perfect-pixell/mobile-boilerplate,xieQin/mobile-boilerplate,texnixe/test,xzcb2008/mobile-boilerplate,globalepub/mobile-boilerplate,xzcb2008/mobile-boilerplate,COBSNAN/mobile-boilerplate,perfect-pixell/mobile-boilerplate,h5bp/mobile-boilerplate,cyprianos/bold