Implemented first part of #17: A HierarchyModifier can now be specified instead of the eliminateHierarchy boolean flag. No new functionality is yet added.

Added preliminary support for bidirectional variables. There are still some known issues, e.g. concurrent updates can still lead to race conditions. This will be addressed soon.

Unfortunatly this currently breaks the ServerHistory module, as it relies on slashes in accessor names. The MicroDAQ module had the same issue but has already been fixed. This fix can be adopted to the ServerHistory module as well.

Fixed wrongly created hierarchies when directly connecting a device to the controlsystem using connectTo(). Now proper virtual submodules are created for each hierarchy level, insted of keeping the slash in the variable name.

fixed connectTo() so it now uses the dynamic/virtual model and thus obeys e.g. eliminated hierarchies etc.

Changed Module::connectTo() to accept also temporary module objects, e.g. as returned by findTag(). As a consequence, the operators [] and () of the modules had to be changed to const.

- allow setting the "eliminateHierarchy" flag in the constructor of a module

This is an interface change which was done in an incompatible way!

added preliminary support for tags to application variables which can be searched for and used to generate virtual modules