install wkhtmltopdf and xvfb
add chef recipe to install wkhtmltopdf (static)
add test for wkhtmltopdf
fix wkhtmltopdf documentation in README
cleanup the wkhtmltopdf recipe
Adds option for custom IP
Merge branch 'wkhtmltopdf' of git://github.com/Dextro/sneakers into Dextro-wkhtmltopdf

Conflicts:
	README.md
[chef extra::wkhtmltopdf] adds checksums
Merge branch 'Dextro-wkhtmltopdf'