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

* add HierarchyModifyingGroup

* VirtualModule: allow nested oneLevelUp etc.; simplify implementation

This is achieved by properly setting the _owner of each VirtualModule (unless highest level).

The simplification comes from then being able to use getOwner() instead of keeping track of "grandparents", and from using createAndGetSubmodule() instead of implementing something similar again in findTagAndAppendToModule().

* DataLossCounter constructor now takes qualified path to trigger variable

* Fix initial msg. Add automatic connection to the LoggingModule.

Now the Logger is a VariableGroup and in the prepare() method an empty
msg is written once. This makes sure the LoggingModule is not waiting
for initial values of Loggers and messages by other Loggers get lost.

* Add message in case on modules with Logger are found.

* Fix test and remove implementation of removed method.

* Do not use hard coded tags but use default tags.

Now all tags given to the LoggingModule are used to look for senders.

The user can now also choose to publish messages only to the control
system.

Refactored.

See 1af92147. Input accessors are now properly part of the ReadAny group which improves the deterministic behaviour.

Instead of holding the modules in a flat list as before, this represents
the ownership of nested modules correctly and prevents possible memory
access violation on destruction.

Currently does not get the modules in a way that they can be downcasted
to test if StatusMonitor, etc

    - Basic structure of test application
    - Added modules
    - Refactoring of StatusMonitor to provide a non-templated base class
    - Needs follow-up, for status see issue #14 and the linked follow-up
      ticket

- ConfigReader is in ApplicationCore.h, but was including ApplicationCore.h itself
- Added include guards to ApplicationCore.h, although it's not stricktly needed (all included headers have one). Might speed up complilation because it makes it easier for the parser.