Changed udev's 50-udev-default to make a scd%n symlink for every sr device

filesystem/udev/rules/50-udev-default.rules

@@ -97,6 +97,7 @@ KERNEL=="fd[0-9]*", ACTION=="add", ATTRS{cmos}=="?*", RUN+="create_floppy_device
 
 # block devices
 SUBSYSTEM=="block", GROUP="disk", MODE="0640"
+SUBSYSTEM=="block", KERNEL=="sr[0-9]*", SYMLINK+="scd%n"
 
 KERNEL=="hd*", SUBSYSTEMS=="ide", ATTRS{media}=="floppy", OPTIONS+="all_partitions"