Update site to use the "open data green"

Open Data has its own green colour in Iceland which should be used
instead of the brown colour provided by the designers in their
prototype design.
Add Icelandic Open Data logo to homepage and breadcrumbs

The site has its own logo which should get added just before the
description of the site on the homepage and on the first breadcrumb
Fix cutoff for the ckan-logo (island.is)

The reason it seemed like it was cut off was the browser scaling.
Fixed by resizing the logo. Could be done better with a better
image source file (vector graphics).
Remove tag blocks from beneath the four main navigational blocks