Fixed one typo and clarified in the configuration examples that it is up
to the client to pick the renew and rebind timers if the server doesn't
send option 58 and 59.
- 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).
