ERT-699: Renamed __load_state -> __load_eclipse_restart
ERT-699: Fixed GEN_PARAM -> GEN_DATA
ERT-699: Removed call to ensemble_clear_internalization()

As part of the function enkf_main_init_run() the function
ensemble_config_init_internalization() was called to clear the
internalization flag of all the nodes. This had the uninted consequence
of clearing the internalization flag of the gen_data nodes, thereby
loosing the REPORT_STEPS: config which has been loaded from the
configuration file.
ERT-699: gen_data_forward_load() can return false.

Due to the weak ordering of the GEN_DATA data containers the
gen_data_forward_load() function previously returned true
unconditionally; if no result file was found that was interpreted as
size 0. If the missing file was indeed an error that would subsequently
lead to a hard crash due to size mismatch in
gen_data_config_assert_size( ).

With this commit the gen_data_forward_load() will return false;
i.e. indicate load failure if no result file is found.