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
Servlet 3.1.0 is definitely not something you want to include. Jetty already brings in 3.0.0 and that is the right version for everything. javax.servlet should not be in the build, at least according to how it's set up now.