2) Remove io.druid files from client

Revert the previous commit.  After going down this path, I realized that extracting things enough to allow Queries to be extended without depending on Druid proper was going to lead down a very nasty path.  So, I've decided against that.  Extending queries will require a tight dependency on Druid proper.

2) Switch DefaultObjectMapper to CommonObjectMapper
3) Create new DefaultObjectMapper in client that has Query stuff registered on it by default

2) Fix group by query to work with new unit test, fixes #232

2) Extract SearchQueryRunner out of SearchQueryRunnerFactory
3) Extract ColumnSelectorBitmapIndexSelector out to make it reusable

1) Delete the files that have moved to druid-api and get them through the druid-api dependency.  Still need to fix Searchable on StorageAdapter, but other than that, everything should compile.

1) ExecutorNode is working, except for the running of the task.  Need to adjust it to be able to run a task and then everything will be wonderful

1) Fix bug with NPE thrown when requesting a dimension on a GroupBy query that is not dictionary encoded