Spark-2447 : Spark on HBase

Add common solution for sending upsert actions to HBase (put, deletes,
and increment)

This is the first pull request: mainly to test the review process, but there are still a number of things that I plan to add this week.

1. Clean up the pom file
2. Add unit tests for the HConnectionStaticCache

If I have time I will also add the following:
1. Support for Java
2. Additional unit tests for Java
3. Additional unit tests for Spark Streaming
I wonder if users will care about auto flush enough that it should show up in the api?  Rather, for those who care, could then not set it in the passed in configuration rather than on a per method basis?  Just a thought if you are looking to simplify.