OCL::logging::Category is not properly overridable

[Hugal31]

OCL::logging::Category offers to override log(RTT::rt_string const&), but it doesn't allow to override the other functions debug, info, etc...

In addition, debug, info, etc... doesn't use log, but directly _logUnconditonnaly2(RTT::rt_string const&), which is not overridable.

A quick way to allow one to override Category would be to make debug, info, etc... use log.