Analytics plugin v1

remove old analytics code from ubersystem, this is all being redone / moved into https://github.com/magfest/uber_analytics

add in an extra place for more stuff to be put into ```<head>``` tag in base.html
Could we name this something more semantic? There are a lot of changes forthcoming in the Bootstrap changes (currently AC branch) and this patch is a VERY different version of the head.html file. I think naming it something like "head_analytics_code" would be clearer when we are manually resolving the conflicts on that future merge.