More generic logger work.
More generic logger work.

* include/fct.h (_fct_loger_evt_t, fct_logger__del,
fct_logger_default_vtable,
fct_minimal_logger__del->fct_minimal_logger__on_delete,
fct_standard_logger__del->fct_standard_logger__on_delete,
fct_standard_logger_new,
fct_junit_logger__del->fct_junit_logger__on_delete): All updated to
use or deliver the generic fct_logger_evt_t object. Renamed some __del
functions to __on_delete to be consistent with the event handler's name.

imb/fctx,imb/fctx,imb/fctx,imb/fctx