* Add benchmarks for varint parsing
* Enable more inlining
* Outline error construction
* Add provided functions to BincodeRead to customize reading of literals
* Add #[inline] to deserialize_byte
* Outline SliceReader::unexpected_eof so that deserialize_varint inlines
* Implement BincodeRead for std::io::BufReader
* Reimplement all of BincodeRead in terms of BufRead-like functions
* Move branch into error-creation function to get below inline threshold
Ben Kimock