patch to add portshaker support to poudriere ports

[Guy Antony Halse]

Hi

We use poudriere to maintain a local package repository, and use portshaker
to merge some local ports into the standard portsnap ports tree.  At the
moment, using

 poudriere ports -u

produces an error, and we have to remember to use portshaker first.

The attached patch to ports.sh introduces a "portshaker" method, and calls
portshaker to update poudriere's ports tree(s) when relevant.  When a user
tries to create the tree, it produces a message reminding them to configure
portshaker(8) as well.

Unless there's a good reason not to, please consider including this in the
default distribution of poudriere.

Thanks,

- Guy
-- 
Manager: Systems, IT Division, Rhodes University, Grahamstown, South Africa
Email: G.Halse at ru.ac.za   Web: http://mombe.org/   IRC: rm-rf at irc.atrum.org
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