"Fix" packages diffutils and rcs with -current

[Antoine Leca]

I have successfully "unbroken" the rcs-5.7 package. In fact I do not
know why it was marked as broken, since I do not had any real problem
(besides low memory); I used ACK as toolchain (and almost nothing
installed, besides svn that is). The binaries are about 15% bigger than
the packages/*.tar.bz2, I assume the latter had been compiled with GCC.

RCS in Minix needs diffutils, at run time (because the basic commands do
not include diff3 nor sdiff, needed for 3-way merges). So I "fixed"
diffutils too (it really boils down adding empty .[br]deps; I cut out
the NLS stuff just in case, but I don't believe there are actual effects.)

In order to make things easier, I moved the installation of RCS to the
/usr/gnu hierarchy; anyway RCS is formally maintained by the GNU people,
and the distributor is the FSF.

I included the diffs (both in svn aka -u format and in official/Posix -c
formats) for both packages.

Remember that both packages add man pages in the /usr/gnu/man hierarchy,
so a proper installation needs to run
makewhatis /usr/gnu/man
after the file copying phase.

The real fine point is that people that have already installed (in
/usr/local) rcs-5.7 will end up with two installations...

Antoine