Add buildbot Makefile for CI.

* Configures Riak with both HTTP and PB, LevelDB backend.
* Runs the 'create_bucket_types' distutils command to create the
  appropriate bucket types.
* Lints using pep8 and pyflakes.
* Runs the entire suite with YZ enabled.

Note this requires basho/basho_buildbot#12.
Merge pull request #324 from basho/feature/sdc/buildbot

Add buildbot Makefile for CI.
Move commands into top-level.
Add top-level .py files to lint.
PEP8 fixes for build
Pyflakes fix for build
Use 'develop' task in buildbot compile step so we are sure to install packages.
Run 2i tests on builder
Fix typo
Ensure installation always upgrades deps
Let's just clobber any previous packages
pip prompts for removal
Merge pull request #325 from basho/bugfix/sdc/buildbot

Fix bugs in build
Add client.close() to explicitly close all pool connections
Use built-in pool clear() method instead of explicitly iterating on client close()
Merge pull request #327 from basho/feature/bch/add-client-close

Add client.close() to explicitly close all pool connections
If a JSON error occurs during key streaming throw the error message into a RiakError
Merge pull request #329 from basho/bugfix/bch/http-json-error

Fix JSON Error during HTTP stream_keys() Operation
WIP CRDTs
Break out the datatypes into separate files for clarity.