Added add_params method
Added querybuilder vows
Added result grouping functionality and tests
Added two new spatial query classes

* Added BoundingBoxSpatialQuery
* Added GeofiltSpatialQuery
* corrected the tests
* corrected the documentation (geodist is no possible value for
SpatialQuery)
Added a softCommit keyword argument

Improved indexing error handling. Also allow softCommits when removing
documents
Added support for join (filter) queries
Buildout2
Release 0.9.0-alpha