xz memory limit override

[Warren Block]

xz(1) has a built-in protective notion about limiting memory usage that 
prevents port building on relatively low-memory computers.  Users have 
experienced this in the wild[1].

Matthias Andree pointed out[2] that there are existing ways to limit 
memory usage: "They can use ulimit(1) -- or whatever their favourite 
login shell offers -- to set soft memory limits."

I submitted ports/148250[3] to add the "-Mmax" option to port xz 
extractions.  There haven't been any squawks of outrage, peeps of 
agreement, or even acks of, uh, acknowledgement.  Hence this message, to 
bring it up again for a status check.

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1. http://forums.freebsd.org/showthread.php?t=15522

2. http://docs.freebsd.org/cgi/getmsg.cgi?fetch=614300+0+archive/2010/freebsd-ports/20100620.freebsd-ports

3. http://www.freebsd.org/cgi/query-pr.cgi?pr=148250