Add error message when parsing a .res file

[Galooch]

While parsing an incorrectly formatted .res file, provide an error with some details to the user. Example .res file (with an extra "=" sign) for reference:

[stevejones72]

Would it be better to just have this as JSON or XML, something that we could properly parse against.

There could be a time where we have code that pulls in legacy text files and outputs the new file, but after a while we stop looking for and parsing this text file? Not sure the scale of tools /programs that expect this quirky text file to be around however.