Proposal: further OptionsNG improvements

[Alexey Dokuchaev]

On Wed, Jun 26, 2013 at 07:12:41PM +0700, Alexey Dokuchaev wrote:
> I've cooked something up just now, take a look at the attached diff.  I've
> only barely tested it, but it seems to work for a few of my hand-crafted
> configurations.  It also handles known options groups (single/multi/etc.),
> tested on www/firefox.

One known limitation of option groups right now is that you cannot have
per-arch or !arch stuff, only :on.  It should not be hard to fix, but I
need to think how to avoid code duplication.  I miss $(call ...) of GNU
make sometimes...

./danfe