Spell revision numbers as "r%ld" in error messages.

Only error messages are touched; test suite and stdout progress output are
unaffected.

* subversion/bindings/ctypes-python/csvn/txn.py (Txn.delete),
* subversion/svnsync/svnsync.c (replay_rev_finished),
* tools/examples/blame.py (blame),
* tools/server-side/fsfs-stats.c (parse_dir): 
    As above.

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1515343 13f79535-47bb-0310-9956-ffa450edef68