[3283] Added DDNS config sections for Kea

    Added secctions for configuring dhcp-ddns to DHCPv4 and DHCPv6 sections.
    Added empty Chapter for DHCP-DDNS server.
[3283] Added intial draft of Chapter 19, DHCP-DDNS Server

Added the first draft of DHCP-DDNS Chapter. Need to fill in the
example configuration section.
[3283] Corrected default D2 server port

Server port default in the dhcp-ddns.spec was incorrect.
[3282] Added Example DHCP-DDNS Server configuration
[3352] Changed calculation of server FQDN flags in D2ClientMgr

D2ClientMgr::analyzeFqdn template method was changed to correctly
set server S and N flags to properly support client delegation.
Added convenience method D2ClientMgr::getUpdateDirections.
Adjusted and added unit tests as appropriate.
[3352] Update b10-dhcp4 to use new D2ClientMgr update direction method

Updated Dhcpv4Srv to use D2ClientMgr::getUpdateDirections method and
adjusted FQDN unit tests to accomodate new client delegation behavior.
[3352] Update b10-dhcp6 to use new D2ClientMgr update direction method

Updated Dhcpv6Srv to use D2ClientMgr::getUpdateDirections method and
adjusted FQDN unit tests to accomodate new client delegation behavior.
Also added a few unit tests that should have been added under 3034.
[3352] Augment DHPC6 FQDN tests to properly check handling of FQDN flags

Unit tests did not detect that Dhcpv6Srv::createNameChangeRequests attempts
to make NCRs when the response FQDN flags indicate that none should be created.
FqdnDhcpv6Srv::testFqdn has been expanded to invoke this method and check the
outcome.
[3352] Added test to not create NCRs if FQDN flags indicate none required

Dhcpv6Srv::createNameChangeRequests was not catching cases where FQDN flags
indicate NO changes should be made. This causes an exception to thrown by
the NCR constructor stating that both forward and reverse flags cannot be
false. Also moved the check up in the method, above of the options loop.
[3080] Initial PostgreSQL patch

 - patch contributed by David Carlier (thanks!)
 - updated to current master
 - fixed compliation issues
 - written developer's guide (pgsql setup steps)
 - many smaller changes
 - still WIP
[3080] IPv4 addresses are now properly stored in integer fields
[3360] Set the lease file location for the Memfile backend.
[3080] Support for fqdn_fwd, fqdn_rev, hostname fields + fixes

 - Added support for 3 new fields, altered schema
 - Fixed bug where empty HWADDR was throwing exception
 - Several clean-ups
[3080] PgSql improvements:

 - UPDATE_LEASE6 query is now working
 - Added bunch of new unit-tests
[3080] MySQL unit-tests reordered (grouped in v4 and v6 sections)
[3374] Reverted the changes made in 3339 and 3373

Files reverted:
[3080] Several queries fixed (now use lease_type parameter)
[3283] Miscellaneous modification to guide as a result of review
[3282] Addressed review comments.

Added discussion of reverse DNS udpates to tables 17.4 and 18.4.
Fixed other minor typos.
[master] Merge branch 'trac3374'

Merges in reversion of 3339 and 3373.