Add scripts for removing log statements before publishing

Profiling this library with nvim and YouCompleteMe opening big files showed that
the log statements(mostly the 'debug' ones) were the cause of significant
performance impact, even with logging disabled at the debug level(about 3
seconds improvement on the benchmark described at #17)

This commit adds a set of scripts that temporarily remove log statements in
order to publish a more optimized version to pypi.

The script used to process the python files were taken from this article:

http://dound.com/2010/02/python-logging-performance/
User eager buffer evaluation while iterating lines

When some python code needs to iterate the lines of a buffer, it is best to
evaluate the lines eagerly to avoid unnecessary msgpack-rpc round-trips.

This is not only faster, but more coherent with vim behavior, since with nvim
it's possible the buffer is modified in the middle of a loop
Bump version
Merge pull request #19 from tarruda/more-optimizations

More optimizations
Process all messages before throwing EOF errors
Merge pull request #20 from tarruda/fix-next_message-error-handling

Process all messages before throwing EOF errors
Bump version
Port to python3

- Refactor imports into relative imports
- Import StringIO from io module
- Refactor iterator .next() as function next()
Fix discover_api

- discover_api() is now a private method called from the Client
  constructor
- Unpacking assumes utf8 encoding for binary sequences
Reset unpacker to utf8 after calling _discover_api

- Once we are done calling API 0 we can recreate the Unpacker
  to use utf8 by default - this is potentially unsafe but it is
  the best short of msgpack 2.0 binary support