* Added a 'RDLIBRARY.READ_ISRC' field to the database.
* Incremented the database version to 245.
* Added 'RDLibraryConf::readIsrc()' and 'RDLibraryConf::setReadIsrc()'
methods in 'lib/rdlibrary_conf.cpp' and 'lib/rdlibrary_conf.h'.
* Added a 'Read ISRCs from CD' control to the 'Edit RDLibrary' dialog
in 'rdadmin/edit_rdlibrary.cpp' and 'rdadmin/edi_rdlibrary.h'.
* Implemented the 'Read ISRCs from CD' option in the full disc
ripper in 'rdlibrary/disk_ripper.cpp'.
* Implemented the 'Read ISRCs from CD' option in the per-track disc
ripper in 'rdlibrary/cdripper.cpp'.