Proposed new structure for XML parsing - Vehicle sensors - ROSInterfaces

Here is the proposed interface for new sensors that enables a developer to implement an interface (subclass specific classes) to add new sensors and/or ROS interfaces.
The commit also contains an example "Echo" driver (SimDev_Echo.h and SimDev_Echo.cpp), which publishes a string from XML config every 1 second. 

To add a new driver/interface a developer need to change CMakeLists.txt and SimulatedDevices.cpp.

As a future development possibility, someone can implement a SimulatedDevice which loads drivers as an external plugin.After this change no changes will be needed in the base code...