First modifications to #13

-First changes to allow association of different databases per channel -
#13
-Identification of messages using its name, not the CAN-ID which is not
unique if more than one channel is used - maybe solves #669
-Uniqueness in message-names is reached by
channelnumber::framename-format, e. g. CAN1::Dummyframe

Still some work to do, to reach perfect solution of #13, but first steps
are done.