Log message:
Catch up to modern pkginstall framework: USE_PKGINSTALL has been dead
for a while now, and *_EXTRA_TMPL are generally not needed anymore.

Log message:
Ran pkglint --autofix over the complete pkgsrc-wip. This changed all
instances like MAKE_ENV+= VAR=${VAR} to the properly quoted form,
VAR=${VAR:Q}, or even VAR=${VAR:M*:Q} if necessary.

Manually reviewed the changes.

Log message:
The Haskell Cabal is is the Common Architecture for Building
Applications and Libraries. It is a framework which defines a common
interface for authors to more easily build their applications in a
portable way. The Haskell Cabal is meant to be a part of a larger
infrastructure for distributing, organizing, and cataloging Haskell
Libraries and Tools.

Specifically, the Cabal describes what a Haskell package is, how these
packages interact with the language, and what Haskell implementations
must to do to support packages. The Cabal also specifies some
infrastructure (code) that makes it easy for tool authors to build and
distribute conforming packages.