Bugfixes:
* `rlp.rawData` was returning a wider than necessary range when
called over a `listElem` result.
* Appending `Rlp` objects to a `RlpWriter` was producing incorrect
results.
New features:
* When the Rlp reading cursor is positioned over a list, you can call
`enterList` to position the cursor to the first list element.
Call `skipElem` to move the cursor further.
* `rlpFromHex` will now accept leading `0x` symbols (often used in the
Ethereum world).
* `rlp.inspect` will now print hex characters by default. Use the
optional parameter `hexOutput` to control the behavior.
