Add a method to compute polygon neighbours with linear barriers

* Added methods in PolygonEntity and PolygonGraph
* Added related tests

(closes OpenFLUID/openfluid#428)
Add a method to compute polygon neighbours with linear barriers

* Added a method for knowing the two PolygonEntity which share the same
Edge 
* Added compute neihbours methods in PolygonEntity and PolygonGraph
* Added related tests

(closes OpenFLUID/openfluid#428)
Update of API documentation

* Cleaned code

(references OpenFLUID/openfluid#101)
Cleaning of Doxygen based documentation

* Escaped special characters
* Fixed API documentation for methods parameters
Removed unused parameter in Doxygen config file for HTML doc
Add new geometry vector format in GeoVectorValue

* Added following wkbGeometry : wkbPoint, wkbMultiPoint,
wkbMultiLineString and wkbMultiPolygon
* Added related tests

(references OpenFLUID/openfluid#430)