Added the cta-mediachanger-mount and dismount utilities

cta.spec.in

tapeserver/castor/exception/MissingOperand.cpp

tapeserver/castor/legacymsg/RmcProxyTcpIp.cpp

tapeserver/castor/legacymsg/RmcProxyTcpIp.hpp

tapeserver/castor/mediachanger/CMakeLists.txt

tapeserver/castor/mediachanger/CmdLine.cpp

tapeserver/castor/mediachanger/CmdLineTool.cpp

tapeserver/castor/mediachanger/CmdLineTool.hpp

tapeserver/castor/mediachanger/DebugBuf.cpp

tapeserver/castor/mediachanger/DebugBuf.hpp

tapeserver/castor/mediachanger/DismountCmd.cpp

tapeserver/castor/mediachanger/DismountCmd.hpp

tapeserver/castor/mediachanger/DismountCmdLine.cpp

tapeserver/castor/mediachanger/DismountCmdLineTest.cpp

tapeserver/castor/mediachanger/DismountCmdMain.cpp

tapeserver/castor/mediachanger/LibrarySlot.cpp

tapeserver/castor/mediachanger/LibrarySlotParser.cpp

tapeserver/castor/mediachanger/LibrarySlotParser.hpp

tapeserver/castor/mediachanger/LibrarySlotParserTest.cpp

tapeserver/castor/mediachanger/MediaChangerFacadeTest.cpp