Move RasterData classes to geotrellis.raster package.
Refactor geotrellis.raster classes into separate files.
Update subprojects to reflect RasterData package change.
Resolve -feature scala warnings.
Remove language feature warnings from tests.
Minor fixes as per code review.
Merge pull request #535 from joshmarcus/topic/rasterdatacleanup

Move RasterData to geotrellis.data and general clean up.