- ChangLog updated (b10-dhcp4 => DHCPv4 server)
 - stand-alone mode removed in Kea4,Kea6
 - getInstance() used instead of server_
 - ctrl_dhcp4_srv.cc: one stringstream instance now shared by all error messages
 - ctrl_dhcp4_srv.h: comments cleaned up
 - Added log message for received configuration
 - kea_controller.cc: Unnecessary header/using namespace removed
 - *.json files are now cleaned up in src/bin/dhcp4/tests
 - added comment that explains lack of tests for Bundy backend
 - kea_controller_unittest.cc now uses the same filename everywhere

Changes also applied to Kea6 (where applicable).