User-friendly saftbusd start

[alyxazon]

Please make saftbusd startable without the additional "libsaft-service.so" parameter. The SO should be loaded as default.

saftbusd libsaft-service.so tr*:dev/wbm* tr2:dev/ttyUSB0 -> saftbusd tr*:dev/wbm* tr2:dev/ttyUSB0