Fix class loader issues for Raptor ORC writer
Move ClassLoaderSafeConnectorPageSourceProvider to SPI
Add utility for parsing Hive partition keys
Change HiveSplit to carry effective predicate
Fix ORC predicate filtering
Set context class loader for Hadoop FileSystem
Remove bad checkCast from DWRF long stream
Improve unknown value stream error message
Fix ORC map writer for null keys

Map entries with a null key are ignored (not rendered)
Reset in-dictionary stream when opening the stripe or row group
Reset slice dictionary stream for safety
Fix BooleanStream skip bugs

Adjust data byte when skipping bits
Fix skip to end of stream
Add toString to OrcInputStream
Add ORC checkpoints

Only flush buffered values if necessary
Fix Hive partition pruning for null keys

Fixes #1864
Remove unused StorageManager H2 database
Do not write CRC files for Raptor
Cleanup Raptor staging directory
Update cassandra driver to 2.1.0

The 2.0.0-rc2 driver has a bug
(https://datastax-oss.atlassian.net/browse/JAVA-254) which gets
triggered when querying through presto.  An exception occurs because the
driver attempts to query a table that no longer exists, and fails.

Cassandra 2.1.0 is the current stable release, so it's probably time to
catch up.  The hector library has been removed and replaced, because it
didn't seem to work correctly with C* 2.1, and the project doesn't
appear to be very active.
Fix formatting