Add new operations that return raster tile loading operations.

These operations for data parallization on a raster return a list of operations
that each load a raster tile, and are designed to replace Raster.getTileOpList().
Remove and replace deprecated map/reducer classes.

This checkin updates all remaining operations that used the deprecated
Reducer1, Reducer2, tiles.Reducer1, and tiles.ThoroughputLimitedReducer1
classes.  This resolves the warnings and makes updating the Raster interface
to remove getTileOpList more straightforward.
Merge pull request #504 from joshmarcus/topic/remove_depreciated_reducers

Remove and replace deprecated map/reducer classes.
Refactor tile loading to use LoadRasterTile.

This checkin adds a new operation, LoadRasterTile, to ensure that
the operation generated by TileSetRasterData is not a closure over
the TileSetRasterData itself -- which would cause the data to be
sent over the network when the operation is remotely executed.

LoadUncachedTiledSet is removed because this refactor makes it impossible
distribute work on a tile set that is not loaded from the catalog (unless
the data is sent over the network as a TileArrayRasterData).

This checkin also tests this machinery on the cached tiled raster in the
test collateral.
Merge pull request #508 from joshmarcus/topic/get_raster_tile

Refactor tile loading to use LoadRasterTile.
Update remote client to load tiled raster from catalog.