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
The former version is correct, although I'd expect the current line to crash out if it ever hit the case where it was out of bounds. Still, going to amend and re-import to see if there is any effect.