docs update after DDNS
tag dhcp6 added
new functions to testing LOG files
New steps for DDNS, clearing leases for DHCP and removed log testing (moved to srv_msg.py)
corrections for DDNS configuration, multiple tsig keys, keys for reverse domain
new way for pool configuration
support for different database backend - mysql, psql
new way of pool configuration
removed functions for log testing, moved to multi_protocol_functions.py
support for BIND9 configuration
suuport for FQDN option improvement
improved parsing response query
log parsing functions
DDNS tests