Keynote-parser

Added more verbose error logging.

Support for Keynote 10.1.

Adds support for presentations with tables.

Includes a fix for serialization of IWA files larger than 64KB.

Fixed a number of encoding issues:
- Added support for properly encoding and decoding `should_merge` message blocks, that seem to use a new feature introduced with Keynote 10.0.
- Fixed an issue identified by kortenkamp where pairs of multi-byte Unicode characters can be mis-identified as a Unicode surrogate pair, causing files to fail to encode or decode.

Includes changes:
- Ignore message_info blocks of type 0 and emit a warning. [18](https://github.com/psobot/keynote-parser/pull/18)