Create directories before copying config files in sysutils/lxmenu.

Add ${PKG_SYSCONFDIR}/menus to MAKE_DIRS to ensure that the menus
subdirectory is created before the example menu file is copied
there.  We use MAKE_DIRS instead of OWN_DIRS since this directory
is probably owned by another package.

Bump the PKREVISION due to fixes in the package install scripts.

(jlam)