DATAMONGO-858 - Add support for common geospatial structures.

Backed the geo spatial structures of SD MongoDB by the new geo spatial structures in SD commons. Deprecated the MongoDB geo spatial types to make users aware that we're going to remove them in one of the following development iterations. Added custom conversions for basic geo spatial types.

We deliberately choose not to let Circle extends CMNS geo.Circle since it would break clients that use the legacy Circle API (getRadius() returns a Distance in CMNS where as it returns a plain double in Mongo).
DATAMONGO-858 - Polishing.

Moved to use the newly introduced geo types from Spring Data Commons. Adde deprecation warning suppression everywhere else.

Adapted Sonargraph architecture description file and split up namespace registration into repository specific stuff and everything else.
DATAMONGO-858 - Revised rendering of geo spatial structures.

Switched back to the old style of rendering (as in 1.4.x) of DBObjects when they are used as values in persistent domain objects, adjusted the GeoConverters accordingly. In order to render geo structures correctly when they are used within a query we now wrap them in a GeoCommand that triggers a different Shape rendering.

We now render the metric that was used in the Distance definition of the radius of a Circle or Sphere.