Confusing naming: mk_url! vs safe!

[cognivore]

Why?

mk_* functions that encode binary() were written first without consideration of the Binary-based constructor.
Binary-based constructor is called safe!.
It's rather hard to figure out which function to call depending on what is the data format we're working with.

How?

• Rename mk_* functions into *_from_raw*.
• Delegate r2* shorthands.
• Delegate mk_* shorthands.