adding canonical urls for simple section fronts and single pages
adding meta data descriptions for category and single pages
strip special characters from excerpt for meta description
fixes meta description for category and skcategory [Scrumwise item #49, used: 5 h, status: To test][Scrumwise item #16, used: 7h]
adding canonical urls to home page [Scrumwise item #49, used: 1 h]
[Scrumwise item #49, used: 1 h] Additional regex to remove special characters and linebreaks from meta description