Update for new proc based API

Signed-off-by: Michael Barton <mail@michaelbarton.me.uk>
Use URL in ADD directive

Signed-off-by: Michael Barton <mail@michaelbarton.me.uk>
Evaluate proc

Signed-off-by: Michael Barton <mail@michaelbarton.me.uk>
Merge remote-tracking branch 'origin/updated-api'