Update pgpool2 to 3.3.3.

Bug fixes:
- installer: Fix bug that install of pgpool-II RPM fails (Yugo Nagata)
- installer: Fix to set up passwordless SSH from apache@localhost to
  postgres@localhost (Yugo Nagata)
- Fix bug that restarted pgpool's watchdog status is regarded as down
  (Yugo Nagata)
- doc: Add mention about "listen queue" and how to increase the "backlog"
  in the num_init_children section. (Tatsuo Ishii)
- Fix bug that watchdog status goes down even when only one of trusted
  servers get unpingable (Yugo Nagata)
- Fix bad performance of unlogged tables detection code. (Tatsuo Ishii)
- Fix primary node detection logic. (Tatsuo Ishii)
  There's a possibility that primary node is not detected. This happens
  in following situation.  node 0: primary, node 1: standby. Node 0 goes
  down. Health checking detects the fact but local status is not updated
  yet. Primary node finding (find_primary_node) runs. Node 0's status is
  yet healthy. Because find_primary_node fails to connect to node 0, it
  immediately returns -1 and fails to find that fact that node 1 is now
  primary.
  Fix is just continuing to look for primary node when fails to connect
  to a node.
- Add raw mode support to pgpool_setup. (Tatsuo Ishii)
- test: Integrate jdbc test to regression test. (Tatsuo Ishii)
- Fix jdbc DML fails when operated in raw mode and auto commit is off.
  (Tatsuo Ishii)
- Fix to output error message when wd_escalation_command fails with exit
  code other than 0 (Yugo Nagata)
- test: Add new regression test for query cache. (Tatsuo Ishii)
- Fix query cache bug with extended protocol. (Tatsuo Ishii)
  SELECT retrieves outdated cache even DML was executed in an expilicit
  transaction. The bug had been there since in memory query cache was
  born. Per [pgpool-general-jp: 1252].
- Add missing entries "relcache_size" and "check_temp_table" to show
  pool_status (Tatsuo Ishii)
- Fix to output error message when if_up_cmd fails. (Yugo Nagata)
- Avoid to send queries to unrelated nodes in streaming replication mode.
  (Tatsuo Ishii)
  Pgpool-II sends certain queries, such as BEGIN, END and SET commands to
  all of DB nodes. However in streaming replication mode, only primary
  node and at most one standby node are only concerned (if primacy node
  is selected as the load balance node, only 1 node is concerned).
- Fix possible buffer overrun problem and memory leak. (Tatsuo Ishii)
- Fix possible buffer overrun. (Tatsuo Ishii)
  Replace strcpy() with strlcpy(). Per Coverity report 1111478, 1111480,
  1111481.
- Add dubug messages for analyzing errors in if_up_cmd (Yugo Nagata)
- Fix freeing NULL. (Tatsuo Ishii)
- Do not enable query cache on materialized views. (Tatsuo Ishii)
- Fix memory leak. (Tatsuo Ishii)
- Fix a segmentation fault in parallel mode with system_db_hostname is
  empty (Yugo Nagata)
- Fix to output debug messages in processing pgpool.conf with -d option
  (Yugo Nagata)
  Previously, some debug messages in pool_get_config() ware not output
  even when -d option was used.
- Fix JDBC exception of prepared statement including now() in
  replication mode (Yugo Nagata)
  With JDBC, when a prepared statement is executed more than
  PrepareThreshold times, the statement is named and Describe message
  is sent after Parse. With named statement, pgpool rewrite now() to
  parameter in replication mode. Hence, rewritten query has additonal
  parameter than original. In this case, ParameterDescription message
  sent to frontend (response of Describe) should include OIDs of the
  same number os original query's parameters. Otherwize, JDBC throws
  ArrayIndexoutOfBoundsException.
- Fix backend error of prepared statement about table which has column whoes
  default value is now() in replication mode (Yugo Nagata)
  When pgpool parses a named prepared statement with default now(),
  timestamps are replaced to additional parameters. So, Bind message also
  should inclued additional parameter format codes. However, when the
  number of original parameter was one, pgpool didn't handle this. This
  caused a error like "incorrect binary data format in bind parameter 2".
- test: Fix a bug of regression test of JDBC that shows OK even when
  this fails (Yugo Nagata)
- test: Add a new regression test for JDBC's PrepareThreshold (Yugo Nagata)
- doc: Add description about parallel mode doesn't support PREPARE (Yugo Nagata)