Prep for 1.1 release.
Add develop dependencies to Gemfile.
Update README
Update DEFAULT_CONTENT_TYPE to appliation/n-triples and add ORDERED_CONTENT_TYPES to environment.
Use #parse_accept_header implementation from Sparql::Rack.
Add nokogiri to Gemfile.
Minor Gemfile change.
Add doc and gem tasks to Rakefile.
Finish 1.1.0