suggested patch for bsd.ports.mk

[Andrzej Tobola]

On Fri, May 13, 2016 at 12:11:47AM +0800, Julian Elischer wrote:
> This patch is pretty self explanatory.
> 
> it allows us to keep patches for various ports separately in a sparse 
> hierarchy while not having to write to the ports tree itself.
> 
> In case the list scrubs hte text attachment (diff) here's the 
> description part of the diff.

>From a long time I am using unionfs - it simpler and allows also
to modyfy/mask all port files - e.g:

  mount -t nullfs -o ro  /pub/FreeBSD/SVN/ports /usr/ports
  mount -t unionfs -o ro /usr/local/ports       /usr/ports

-a