Not recognized commands in config files should give errors

[zuckerruebe]

If I have something like

assign "..\path\to\file.csv" unitProfile

in a run.config, pytrnsys should tell me that it doesn't recognize the "assign" and refuse to continue. Currently, it just ignores it and I have no idea why the assign didn't work.

OK, we could be having a discussion about whether commands in config files should be case-insensitive, but there is the general problem that unrecognized commands/keywords in config files are just silently swallowed (a line like "foo bar baz" will just go through without pytrnsys complaining). That needs to be fixed. If that's fixed, case-sensitivity of recognized keywords becomes a non-issue, because the user will get a nice error message if they get the casing wrong.