* add items to transcript

* add additional items to transcript

* fix benches

* cargo fmt

* remove asserts; return result objects

* bump version

* clippy

* Update to latest Rust and fix Clippy warnings

* cleanup

This:
- introduces a small [thiserror](https://github.com/dtolnay/thiserror)-powered enum to improve ProofVerifyError's messages,
- refactors point decompression errors into a variant of that enum, thereby suppressing the panics which occur when decompresison fails.
- folds other panics into the Error cases of their enclosing `Result` return