case for opendcc GBMboost and GBM16T

case for BIDIB opendcc GBMboost and GBM16T central unit and feedback system
(http://www.opendcc.de/elektronik/gbmboost/gbmboost.html ,
http://www.fichtelbahn.de/gbm_index.html )

mod1: added mounts to bottom part, snap-in optimized, enlarged the opennings for the connectors

mod2: increase of wall thinkness and additional wall stabi, emergency stop switch mount added (3N-files)

mod3: new joint design, enlarged space to the electrical components to simplfy the assembly (3R-file