Add a module.cnf system

[uliska]

\loadModule should be able to read a module.cnf if found. components should be an optional key to add to that.

The point of this addition is on the one hand to add the option to attribute a module to contributors, on the other hand it may be used for "introspection" functions that can be used to "debug" or find out what is available, and it can be used by Frescobaldi.

This should be totally optional, so only if a module.cnf is found in a module directory it should be parsed. However, mandatory and optional keys should be checked as well (although it has to be discussed what mandatory options should actually be)