Navigation tweak to handle URIs and relative paths

[imranh2]

Lets you have arbitrary links (URIs) in your navigation while also allowing you to just have short simple relative paths for when you need them

  navigation:
    - title: About
       url: "/about"
    - title: My Cool FTP server
       url: "ftp://ftp.imranh.co.uk"

[samarsault]

Both the cases should work without this change. Were there any issues in your case?