Renamed all occurrences class and type components in event structs to vscp_class and vscp_type.h
This will break code outside the repository. But it will reduce name clashes when using arduino and
C++ thus worth the trouble.

To update your firmware simply search for '.class' and '.type' and replace it with '.vscp_class' and
'.vscp_type' respectively all through your project.

Signed-off-by: Stefan Langer <langer@microanalyt.de>