Remove the CDClientDatabase::ExecuteQueryWithArgs() function and replace
it with CDClientDatabase::CreatePreppedStmt().
This prevents a developer from accidently using %s, or incorrectly
passing std::string, and causing a silent error.
* add HandleUnmanaged overload to account for skill source
* add source to buff damage skill call to credit players for kills
* use LWOOBJID_EMPTY default arg & behaviorcontext constructor