A working importer for the Instapaper service. The importer imports
bookmarks, full text articles, and highlights. A blob item handler for
Instapaper highlight permanodes is included to show summarized highlight
content from the server UI.
Also, this CL updates github.com/garyburd.com/go-auth to rev
bca2e7f09a178fd36b034107a00e2323bca6a82e in order to get support for
XAuth requests.
Fixes#1208
Change-Id: I72e0c40b245c7eec4a44bb475fcaa96a0ee9a1c5
Angel