Better debug info if Post_Point fails validation
Make sure Point_Geometry/Int/Point inherit rules from Post_Value
Add WKT validation to Post_Geometry model (and extend Post_Value)

Adding gisconverter submodule for WKT validation
Convert Post_Point get/set to use gisconverter and handle WKT or array

* Removing geoPHP submodule
* Add tests for Post_Point validation
Test and Fix loading and savings of Points and Geometries in Posts

* Load points seperately from other values using ORM
* Load Geometry value as WKT
* Add a point and geometry attribute to the test form
* Add point and geometry values to the post tests
* Minor improvement to error message when encoding JSON response