Log Message:
-----------
Add "troubleshooting" section.
Modified Files:
--------------
pgpool-II/doc:
pgpool-en.html (r1.60 -> r1.61)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgpool/pgpool-II/doc/pgpool-en.html?r1=1.60&r2=1.61)