[PATCH v2] Fix failing three way diff for properties

[[[
Fix failing three way diff for properties when invoking diff-full (df)
in the interactive conflict resolver.

* subversion/libsvn_wc/util.c
  (svn_wc__cd2_to_cd): All the usual files needed in a three way diff is
    made available for properties as well as markers for binary format
    and mime.
]]]

After this patch a binary property will be displayed when invoking
diff-full. I intend to fix this in a subsequent patch. Perhaps adding
newlines when there is none to enhance readability. Since we're not
using the diff for manually resolving the conflict.

The three way diffs for the propties are sotred in .prej files in this
format:

[[[
Trying to change property 'prop' from 'dog' to 'horse',
but the property has been locally changed from 'dog' to 'cat'.
]]]

Bert wrote in an earlier mail [1] that in WC-NG there will be no .prej files
but that the information will be stored in the database. That way we can
view the three-way diff any time we want and won't have to resort to
those pescious .prej files.

He continues:

[[[
We still need to design some way to make all this available in the
commandline client. One way would be to make 'svn resolve PATH' run the
interactive conflict handler on all the remaining parts of a conflict,
but another way to see the conflict-version properties in a non
interactive way would be nice.
]]]

Is a suboption to svn di a good way to view the conflict in a
non-interactively way?

/Daniel

[1] http://svn.haxx.se/dev/archive-2009-10/0816.shtml