shared_io_utils vs printio vs read-write-pipe

A utility to provide more convenient `Read` `Write` `Seek` `Debug` `Cursor` that could be shared, e.g. `SharedReader`, `SharedWriter`, `SharedReadWrite`, `DishonestReader` for modifying data using closures when being called `read()`, `CombinedReader` combines two readers but you can 'slice' the readers to make it only able to read parts of them, `CursorVecU8` have a better formatting behavior, `SharedCursor` shares a `CursorVecU8`, `MultistreamIO` allows you to switch its streams to read or write, `SharedMultistreamIO` shares the `MultistreamIO`. All of these 'shared' version are used for the 3rd party library to read/write and you can capture the data or modify the data.

A simple library to intercept a Reader or Writer and print it to something on its way in or out. Useful for debugging.

A trait for objects implementing Write, to write all content from a Read object.