coverity#1158416 Uninitialized pointer field

Change-Id: I5c1b07bd3898e89141fe3c3c8f8b63b81513a97e
coverity#1158410 Uncaught exception

mdds::general_error is thrown but is luckily inherited from std::exception so
use the new ability of 0bc89aac4c64bb833e387657f680e194c26aef97 "cppumaker:
Allow UNO interface functions to throw std::exception."

Change-Id: I2c1d30e0806281d43c7bec103d4c85e1799c5b4f
coverity#1158408 Uncaught exception

Change-Id: Ie0a3cfeedeb386e72749997e6a4bdf8b6c515be2
coverity#1158407 Uncaught exception

Change-Id: Ib8830798250b9c4f143743de4389260fceb44aa3