bsd.linux-rpm.mk: Wrap a long line.
bsd.linux-apps.mk: do not insist on 2.6.X when overriding non-base ports.
bsd.linux-apps.mk: add c6 as valid value for overriding non-base ports.
bsd.linux-apps.mk: minimum FreeBSD version is 8.3, so simplify comment.
bsd.linux-apps.mk: do not re-introduce definitions for removed gtk1 port.