Add ramfs support

[123aezakmi123]

I would like to use ramfs instead of tmpfs since ramfs can't swap. So I created a mount point in /etc/fstab
ramfs /mnt/transcodes ramfs nofail,mode=0777 0 0
In transcode.cleanup.sh I changed this line with the size in bit DIR_SIZE=1073741824 (1GB for me) so in this way I can limit ramfs which has no size limit.

Obviously bufmon.sh doesn't work because df $TRANSCODES_DIR -ha doesn't work with this type of filesystem but by checking manually, the limit was never exceeded. I also tried with 100/256/512MB limit.

Could it be officially supported?

[RTUnit]

Interesting, I did not know that tmpfs can use disk space instead of actual RAM. Thanks for bringing this up. Will not be able to test ramfs so soon (in a few weeks at least). But if you can make it work sooner them please report it here.