Remove a duplicate include from PointBuffer.hpp

Just a little Monday cleaning.
add PCL VoxelGrid as a decimation option (not the default)
Merge pull request #454 from chambbj/voxel-grid-ctx

add PCL VoxelGrid as a decimation option (not the default)
Merge pull request #456 from gadomski/rxp-driver

Add the rxp reader
Use long, not int32_t, for rxp moving average

This seems slightly clearer to me, per @abellgithub's comments on
51b11498cdc4f11c765cf723625100d826aa4da6.
Catch bad_numeric_cast, rethrow better