Add a README for l3build


git-svn-id: http://www.latex-project.org/svnroot/experimental/trunk@5039 de43f980-851b-0410-b2f7-c40aca1f87e0
Add a license to l3build.lua

Presumably the LPPL applies here: what do we do about the glob stuff?


git-svn-id: http://www.latex-project.org/svnroot/experimental/trunk@5040 de43f980-851b-0410-b2f7-c40aca1f87e0