[PATCH] Issue #3919: fix for spurious property conflict during merge

Hello -

Attached is a patch for issue #3919 [1]. Please review when you have a
chance. Thanks!

Possible commit message:

[[[
Fix issue #3919. During a merge of a property, add a check against the
incoming new property value and the working copy value. If they
already match, then the merge trivially succeeds.

* subversion/libsvn_wc/props.c
  (apply_single_generic_prop_change): Do nothing if the incoming new
property value already matches the working value.

]]]

[1]: http://subversion.tigris.org/issues/show_bug.cgi?id=3919

Best regards,
BN