Use the un-proxied version of geoserver API
Adds SVG link

Adds an SVG link based on the width and height set in the content_url helper

closes #16
Adds a shapefile link to item view

Adds a link helper for shapefiles and adds it to the item view

closes #14
Adds a high-res image link

Uses a 1024 x 768 tiff for high-res image

closes #15