0.3.4.a

Corrected a bug that did not allow stats to be computed on polygons
that are too small. In particular, if the centroid of the polygon was
not in a cell, then no stats would be computed, even if part of the
cell was covered by the polygon.
Added all_touched option to raster_stats
Merge pull request #30 from ozak/master

Added all_touched option to raster_stats