[3195] Initial support for unicast added.
[3195] Unicast log message bumped up to INFO.
[3195] Failed unicast bind no longer terminates control session.
[3195] Bugfix in activate IPv6 interfaces

 - exceptions are now more verbose
[3195] Socket selection for outgoing traffic improved
[3195] Two unit-tests implemented for unicast sockets
[3195] ChangeLog updated.
[3195] BIND10 Guide updated.
[3195] Changes after review:

 - Guide updated
 - Iface::addUnicast() now refeses duplicates
 - addUnicast and clearUnicasts are now commented
 - new unit-tests
 - argument for addActiveIface is const reference again
 -
[master] Merge branch 'trac3195' (DHCPv6 unicast sockets)

Conflicts:
	ChangeLog