Allow WANT_PGSQL=lib to be combined with other pgsql components.

[matthew]

Summary

WANT_PGSQL=lib adds a LIB_DEPENDS on postgresglXY-client (this is also
the default when WANT_PGSQL is not defined). Compare to
WANT_PGSQL=client which only adds a RUN_DEPENDS on
postgresqlXY-client. 'client' can be part of a list of different
components, but 'lib' is ignored if any other terms are specified,
which seems an arbitrary and incorrect restriction.

WANT_PGSQL=lib allows expressing that the port links against
libpq.so.X rather than just needing one of the client programs like
psql(1) at runtime. However, other than that there is little
practical difference between 'lib' and 'client' on the resulting pkg.

[mat]

Mk/Uses/pgsql.mk

133

This can simply be ${WANT_PGSQL:Mlib}

[crees]

Ok, fine- I wrote this bit before pkg did all the cool lib bump stuff.

Please commit Mat's version. I'm sure an exprun can't possibly be needed??

[matthew]

• ${WANT_PGSQL:Mlib} is sufficient, doesn't need '== lib'

[matthew]

This was already committed, but there seems no way to persuade Phabricator of that fact, so the only option is to abandon it.