Inconsistency between parse_files() and parse_file()

[sonofwatt84]

There are apparent differences between how parse_files() and parse_file() handles data. While, it's unclear how substantive these differences are, it introduces uncertainty in how comparable steady state and transient results are due to differences in how the inputs are handled. parse_files() should probably just call correct_network_data!(), like parse_file(), instead of calling the subfunctions used correct_network_data!()