Support parsing kit files

[struthiocamelus]

Changes

• Support parsing kit files
• Minor change to SongMemory for consistency: I'm using TryFrom in the kit, so I want SongMemory to support TryFrom as well. Deprecated the existing from_bytes. Bonus is that now it's a trait and not just a function.

[struthiocamelus]

snap.kit is a kit with one sample - a recorded sound of me snapping.

I hereby dedicate it to the public domain 😄

[struthiocamelus]

I figure I ought to write a little more about the TryFrom vs. bare impl helper -

What you gain with implementing TryFrom is:

• Idiomaticity - TryFrom is a known pattern and its function can be assumed.
• Portability - That these structs have TryFrom impls means that someone needs no knowledge of the underlying struct to accept something that can TryFrom<[u8]>. Shared idiomatic traits comes in very helpful when pulling two disparate packages together.