Use https gem source as per recommendation
Change build dir to "output"

This is consistent with modern nanoc generated sites.
Rename config.yaml to nanoc.yaml

This is consistent with modern nanoc behavior.
Upgrade nanoc to 3.6.4
Remove obsolete index.html and atom.xml
Integrate updates from newer nanoc config files
Newlines to make config easier to read
Use guard and gsl
Add Google GWT verification
Guardfile for compilation
Ignore new output dir
Change sitename to reflect new github domains
Add sitemap to helpers
HAML sitemap item
Rules to compile and route sitemap