Low: pgsql: add a function to retry command
Low: pgsql: change name and specification of exec_func_with_timeout

- change function name from exec_func_with_timeout to exec_with_timeout
- change specification of exec_with_timeout to conform it to exec_with_retry
- exec_with_timeout outputs more logs
- increase in performance
Low: pgsql: Share output of crm_mon. If crm_mon fails, RA re-exec it
Low: pgsql: improve error handling of crm_xxxx commands and reload_conf()

- if crm_xxx command fails, retry executing it
  because the number of IPC connections reaches maximum,
  crm_xxxx commands fail.
- if reload_conf() fails, retry it, because the failure is critical
Low: pgsql: report failed query and return code

- report_psql_error() reports given message to distinguish failed query
  when using replication mode.
- change some loglevels from warn to err when calling report_psql_error(),
  because warn should be used for starting up PostgreSQL.
Low: pgsql: simplify picking out data status
Medium: pgsql: set only one node into sync mode when using 3 nodes or higher

Only one node can be sync mode to avoid data loss when using 3 nodes or higher.
See http://www.gossamer-threads.com/lists/linuxha/pacemaker/85077?do=post_view_threaded#85077
Low: pgsql: remove unnecessary code which is used by multiple synced nodes
Low: pgsql: control slave status once again when sync mode is changed

execute control_slave_status() once again to improve performance
of catching up slave status.
Low: pgsql: inhibit unnecessary log
Merge pull request #272 from t-matsuo/fix-improve-and-speed-up-pgsql-RA3

Fix a bug, improve and speed up pgsql RA