Feature Request: Add hash 'pattern' option in Episode Naming

[twiz-git]

Since it'd typically be used to check for accidental corruption, and not a security verification, I think there is no need for something like SHA-512 over SHA-1/MD5. and some people might like the shorter CRC32.
This will obviously incur some processing time, but in my non-indepth testing on a Raspberry Pi3 (with a 5400RPM drive) a ~450MB file took about 11 seconds for MD5sum, SHA1sum and CRC each, and on an old PC running Windows a 4GB file took roughly the same time.