Changes in CUPS v2.1rc1:

• Added support for 3D printers (basic types only, no built-in filters) based on PWG white paper.
• Fixed bugs in the new journald support (Issue #4655, Issue #4658, Issue #4661)
• Fixed domain socket support on Linux (Issue #4679)
• Fixed signal handlers in the dnssd and usb backends (Issue #4671)
• in sections now applies to all operations when used by itself (Issue #4659)
• Configure script changes for systemd support (Issue #4669)
• Updated autoconf sources to use newer form of AC_INIT (Issue #4664)