* Target session attr feature for storage
Storage host section is now accepts a comma-separated
PostgreSQL hosts list, in format "host2,host2"
or "[host1]:port1,host2" etc.
Storage structure now holds pointer to host, which connection was acquired.
This is required to cancel`s queries to work fine.
Target session attrs policies added:
read-write
read-only
any (default)
Target session attrs uses pg_is_in_recovery function to
check if host in primary or replica. in_hot_standby option is not checked yet.
reshke