Declare Slice explicitly in pom dependency management
Add SliceArrayBlock

SliceArrayBlock is a VaraibleWidthBlock wrapping a Slice[] instead of a single Slice.
This is useful for implementing dictionary encoded columns.
Add support for lazy blocks

Add LazyFixedWidthBlock and LazySliceArrayBlock
Add OperatorContext.recordInputWallNanos(long)
Add new ORC reader implementation
Add metadata abstraction for ORC
Extend custom ORC reader to support DWRF
Switch default file format to ORC
Make HiveRecordSink store uncompressed
Benchmark Hive input formats directly
Add support for NULL parition keys
Add support for TIMESTAMP in Hive partition key

Fixes #1474
Add Hive write support for varbinary, date and timestamp

Fixes #1425