moved VariableNetworkNode member to AccessorBase class, so the network node information can be accessed also when having only the pointer to the base class

allow specifying the array length for direct connections between device and control system (as the type is already defined in this case)

- fixed copying only the first element in some situations

Added description field to the variables. It is currently ignored and will be added to the XML file in a next step.

reading back the variable from the device currently does not work, so instead directly pass it to the simulator module.

partial fix for problems due to moving to new ControlSystemAdapter structure: allocate and use the buffer from the NDRegisterAccessor
tests still do not pass

Adapation to the unified versions of ControlSystemAdapter and DeviceAccess.

Status: Library compiles, tests do not yet compile.

Revert "Capture only coverage data for the current project in the first place, instead of extracting it from all coverage data in a second step. This seems to be needed as extraction spuriously might fail in some cases."

This reverts commit ce14dcd0.

Reason for the revert: The change did not work on Ubuntu 12.04 due to an old version of lcov.

Capture only coverage data for the current project in the first place, instead of extracting it from all coverage data in a second step. This seems to be needed as extraction spuriously might fail in some cases.