change ArgWritable to convert to/from RasterData
Fix Eclipse autoformatting
Handle BitArrayRasterData conversions to/from byte array
Merge pull request #667 from ameetkini/argwritable

change ArgWritable to convert to/from RasterData
Merging from master.
Merge pull request #670 from geotrellis/next-release

Merging in toByte logic from next-release