StepMania beta 4a is annoying

Yeah...I'm pretty sure even in beta 3 the theme had a knack for dumping the same lua errors to console. The reasons probably being no different than what was discussed here earlier.

Edit: Fixed typos. Don't sleep and type.

Yes, it does spew all those errors to the log file in beta 3. You can find it in %APPDATA%/StepMania 5.0/Logs/log.txt and see for yourself.
Additionally, I've fixed hundreds of places where a theme mistake would cause Stepmania to crash outright so that they show an error instead.
(I'm not even exaggerating, here's the first pull request for error reporting. Searching for "ASSERT" and "RageException" turns up 94 total, and that's not counting all the ones I've found since then.)