soda-source written into the bus structure of trb3.

soda-source written into the bus structure of trb3.
Register access is implemented making use of regIO-example  (by Peter Schakel)
controlling LEDs on trb3; i.e. slowcontrol is tested here.
No more errors in Synplify so this should result in a downloadable and working firmware.
First test is access to trb with trbcmd.

ToDo next:
- design/implement/test reply-checker
- make new project for SODA-client or use conditional synthesis ("generate if")