panic cleanup

[garious]

We're too cavalier with calls to expect() and unwrap(). We're using them safely for the RwLocks, but most others should be acknowledged or added to the return values.

[jackson-sandland]

For the unsafe calls to expect(), is a panic still acceptable on err as long as there are good error messages? Since multiple calls to unwrap() will print the same panic message, doesn't it make more sense to use expect(), instead of unwrap(), with an error message detailed enough to indicate where the panic occurred?

[garious]

I think replacing every call to unwrap() with expect("something unique") would be a first good step.

[jackson-sandland]

Sounds good. I'll start there. I'll leave off replacing calls to unwrap() in tests / benchmarking.

[garious]

Thanks @jackson-sandland!