pgbouncer - pgbouncer: make IOBuf use unsigned ints

Log Message:
-----------
make IOBuf use unsigned ints

Modified Files:
--------------
pgbouncer/include:
iobuf.h (r1.2 -> r1.3)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgbouncer/pgbouncer/include/iobuf.h.diff?r1=1.2&r2=1.3)
pgbouncer/src:
sbuf.c (r1.27 -> r1.28)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgbouncer/pgbouncer/src/sbuf.c.diff?r1=1.27&r2=1.28)