* uufuzz: create a crate with the common functions
* uufuzz: move the fuzz-common functions
* uufuzz: polish the crate
* adjust the fuzzer to use uufuzz
Minor manual cleanup - inlined many format args. This makes the code a bit more readable, and helps spot a few inefficiencies and possible bugs. Note that `&foo` in a `format!` parameter results in a 6% extra performance cost, and does not get inlined by the compiler (yet).
