[GEOT-2791] ShapefileReader uses a safer memory/buffer-address translation.
Added testcase for reading sparse shape files.
Added testcase for reading sparse shape files.
Fix for GEOT-2791 ported to shapefile-ng. Fixes IllegalArgumentException in buffer when reading sparse shape files.
Merge pull request #134 from DieterDePaepe/master

[GEOT-2791] Fixed IllegalArgument in buffer when reading a sparse shape file