devel/libvirt: version update and security fix

• update to 1.3.0
• add fix for CVE-2015-5313
• improve sample file renaming to do that by moving files in post-install rather than patching Makefiles
• add an rc script for the new virtlogd daemon. It is required for the qemu driver if you have stdio_handler = "logd" in qemu.conf (default)

Security: CVE-2015-5313