Prepare for handling pkg state with files. So it requires having the
path defined before declaring targets. In addition, it cleans up the
old git-download target.
This "ISC License" is the value found by github
7d419e1fa4/LICENSE
A permissive license lets people do anything with your code with proper
attribution and without warranty. The ISC license is functionally
equivalent to the BSD 2-Clause and MIT licenses, removing some language
that is no longer necessary.
