Demo tag lists should link to the search page

[aron.carroll]

Instead of pointing to /tags/{tagname} all tag links should just point to a dataset search filtered by that tag.

Examples are on the homepage and the dataset pages.

[toby]

ok I've done this and also unified the tags

they are now tag/class

<ul 'tag-list'>
<li>
<a 'tag'>

on home page tag was on <li> not <a> slightly changes the spacing please review

[aron.carroll]

Looks okay to me