Create OrthancServer.main.cpp

Exceptions with description. Otherwise server dies without informing the cause of death, i.e. before:
E1205 16:47:57.365274 30204 main.cpp:687] Native exception, stopping now
after
E1205 16:49:51.910228 30268 main.cpp:685] Exception: [locale::facet::_S_create_c_locale name not valid]