Remove useless USES

Reported by:	Oliver Pinter


git-svn-id: svn+ssh://svn.freebsd.org/ports/head@375201 35697150-7ecd-e111-bb59-0022644237b5
Conditionally assign variables so that slave ports can override them.

Approved by:	imp


git-svn-id: svn+ssh://svn.freebsd.org/ports/head@375202 35697150-7ecd-e111-bb59-0022644237b5
Bump PORTREVISION to 2 to reflect libgcc being added to the package.
(The prior attempt to bump the revision failed to override the master
port revision.)  Also now that the master port allows overriding target
and configure variables, do the overrides before including the master
rather than after.

Approved by:	imp


git-svn-id: svn+ssh://svn.freebsd.org/ports/head@375203 35697150-7ecd-e111-bb59-0022644237b5