Support for search_type query string param to searches.

Conflicts:
	elasticutils/__init__.py
Fix cloning S with search_type, add tests
Change search_type to be a chainable method
Have bulk_index fail on error instead of ignoring it
Attach facets to search result objects
Merge pull request #187 from HonzaKral/bulk_index_fix

Have bulk_index fail on error instead of ignoring it
Expand comments
Explicitly ask Elasticsearch for two shards

At least two shards are necessary for testing query_and_fetch search
type. Make sure that even if the global ES configuration only specifies
one shard, the test still works.
Make _build_query() accept dicts as sort values
Merge pull request #189 from diox/dict-as-sort-value

Make _build_query() accept dicts as sort values
Added support for a `size` parameter to facets.

Fixes #192.

You can now limit the number of facets returned by passing the `size` parameter:

>>> s.facet('category', size=5).facet_counts()

Signed-off-by: Kevin Stone <kevinastone@gmail.com>
IndexerTasks: Add additional kwargs.
Add support for parsing dates with microseconds
IndexerTasks: Swap order of kwargs in indexer task.
Add tox.ini and fix dev requirements
Fix test refresh so it waits until cluster is yellow
Update CHANGELOG, CONTRIBUTORS and add note about facets attribute
Merge pull request #197 from davidlundgren/IndexerTasks-AddKwargs

IndexerTasks: Add additional kwargs.
Add new contributor
Update CHANGELOG