Speed up input stream processing in config parser and others that read single bytes from a stream.
Speed up input stream processing in config parser and others that read
single bytes from a stream.

* subversion/libsvn_subr/subst.c
  (translated_stream_read): Add an optimized code path for single byte read
    requests.

Patch by: Stefan Fuhrmann <stefanfuhrmann{_AT_}alice-dsl.de>

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion