use the new readLatest(), which has been added to the latest DeviceAccess version, to implement the naturally expected behaviour when using a push-type variable with a poll-type accessor

When attaching a trigger to a node, the resulting triggered node is stored and later returned when the same trigger is attached again to the same node. This fixes crashes when joining two networks sharing the same node triggered by the same trigger, if the triggering node was technically different.

Instead of making the DeviceModule return the same VariableNetworkNode for the same register, an optimisation step before realising the connections (but after all connections have been defined) is performed. In this step, all networks sharing the same (device-type) feeder will be merged. This is more flexible and avoids problems with (potentially different) triggers etc.

A DeviceModule now returns the same VariableNetworkNode when asked for the same register multiple times. This leads to a new restriction that registers can now only be either read or written. This restriction can be mitigated by using the logical name mapper to create an alias of the register. This has been implemented for the tests and the demo application.

- moved the sleep in Application::testableModeLock() so it helps better against false positive stall detections
- added comments to the growingly complex code of Application::testableModeLock()

preparation for future changes: The TestDecoratorRegisterAccessor now gets a ProcessArray as argument, not the more generic NDRegisterAccessor. This allows it to use specific features of the ProcessArray.

detect stalled tests and print a list of variables which contain data not processed by the application

- prevent spamming of some messages in debug testable mode

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.

fixed using out-dated strstream, fixed dump() which was not passing the stream to dump into on to internal calls of VariableNetworkNode::dump()

Made some exception descriptions more elaborate. To achieve this, the dump() functions have been extended to allow writing to an arbitrary ostream.

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

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

added function to flatten teh hierarchy, renamed eliminateHierarchy() into setEliminateHierarchy() for better clarity

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

fixed duplicated triggers when triggering multiple transfers with the same application variable (e.g. as used in tests frequently)