[help-recutils] Homebrew formula to build from HEAD

[Paul Rankin]

Given that the latest stable release of recutils (1.7) is a bit old now, it 
would be great for macOS users installing via Homebrew to be able to install 
from the development repository with a --HEAD switch.

The Homebrew formula: 
https://github.com/Homebrew/homebrew-core/blob/master/Formula/recutils.rb

Thanks,

-- 
Paul W. Rankin
www.paulwrankin.com