[geotk] Geotk 3.16 released

[Martin Desruisseaux]

Hello all

The much delayed 3.16 release has been deployed today. This release feature 
performance improvement and bug fixes. In particular:

- Raster reprojections are now much faster when MathTransform derivative
   are available (derivative are not yet implemented for all MathTransform.
   I will explain later in a blog why we use derivative).

- Many bug fixes when dealing with multi-dimensional CRS. For those who
   use 3D and 4D CRS, Geotk 3.16 is a recommanded update.

	Martin