Merge pull request #7 from lvicentesanchez/master

Tag spark dependency as provided.
Better error message when attempting to write to a table that doesn't exist. Fixes #1.
Merge pull request #10 from datastax/issue-1

Better error message when attempting to write to a table that d...
More and better logging. Using org.apache.spark.Logging instead of log4j. Fixes #13.
Merge pull request #14 from datastax/issue-13

More and better logging. Using org.apache.spark.Logging instead of log4j...
Using a PreparedStatement make createStatement method compatible with Cassandra 1.2.x.