Changes the build to only use CDH4.6 dependencies.
Comments out large thrift struct tests since they don't work with
parquet-1.2.5-cdh4.6.0
Changes parquet-tools version to 1.5.0.

Cloudera won't publish parquet-tools until CDH5.2 and we gave up trying
to persuade them after arguing with them for a week.
Adds Backward compatibility tests for parquet 1.2.5-cdh4.6.0.