- Implemented but not tested yet
- All existing tests passing

* Not implemented yet. Currently always return false.
* Test exists and compiles, but is failing due to the missing implementation.

This is changed behaviour introduced with c9948142

Paths starting with "/" will be stripped of the leading slash now. Empty paths (or a single slash) will be interpreted to refer to the Module itself and hence return *this.

This logic is otherwise ofter required in code which uses submodule().

Before it had to be stripped for all use cases anyway, so it is better to leave it out from the beginning.

so dependencies can already ask for the new features

It was handing out only those control system accessors which do *not* belong to the particular ControlSystemModule, because the if condition was inverted.

Multiplier module: add modern constructor accepting qualified path names of input, factor and output