Preliminary support for Gopher

Currently parses information and text items and retrives files.
gopher: Handle binary, directory and error types
gopher: Handle info resources and add proper title

We now create a proper title from the error message, or
the TITLE resource if present.
gopher: Handle some more item types
gopher: Handle audio and video types, add a default case
gopher: Add a stylesheet

Modified version from my attempt at adding gopher to NetSurf.
gopher: remove debug printfs
gopher: Add TODOs
gopher: Set a default MIME type to force downloading