Build QoL

[hohle]

Several quality of life changes for building:

• The Makefile has a help target which will show common targets. Targets with comments starting with ##@ will be included in the help output.

• The check target now has colored output.

• Added check_disk target which will check hashes of extracted disk contents (useful for those who dump their own discs)

• Added dump_disk target which will create a bin/cue pair from an original disc.

[hohle]

make help:

make check:

[hohle]

The implementation I chose was @BlackHole1's with some tweaks for portability and terminal compatibility from that same page.

I forgot that splat checks the SHA. I'll make sure it's present in all of the overlays for versions I have access to and remove the targets.