Requirements on library configuration

[kraigher]

There is a need for a configuration file format to declare which files belong to which libraries.
For the language server the configuration file will have to be placed in the workspace by the user.
I think TOML will be a suitable format for the configuration file format using this rust library https://docs.rs/toml/0.4.8/toml/.
In the absense of a configuration file the user would be warned and semantic analysis would be turned off giving the user just syntax errors.

The command line parser demonstrator could also read the configuration file. Is it still usable for the parser demonstrator to be able to read files as a list in argv without library information to just perform syntax checking? Maybe the parser-only without semantic analysis should be a separate binary if we need it. You have started to use the parser binary @mbrobbel, what do you think?

The data structure for the library would have to support clearing all design units from a certain file and updating them again to work with the language server when a file is edited and design units are removed or added.

[kraigher]

I have decided to use toml as the configuration format.