WIP: TimeSeries RasterRDDs

Summary of things done:
- RasterRDD is now generic on ID type
- Mosaic and pyramiding code moved to RasterRDD functions
- Support for TimeBandTile ((TileId, TimeId), Tile) in saving and loading from accumulo
- Refactors to AccumuloFormat, now it works on whole RDDs rather then individual records
- Accumulo and HDFS Catalogs now share an interface and can be composed under one object
- Move RasterRDD and supporting files into geotrellis.spark package geotrellis.spark.rdd is now gone
- Pruning of dead code
- Accumulo catalog unit tests include all likely fail scenarios
- TimeId should be JodaTime date and written in ISO8601 format instead of "a Double"

Issues to be resolved:
- Upstream merge