processing Select By Location operators

[Arnaud Morvan]

Processing algorithms like "Select By Location", "Extract by Location"
have been enhanced with some new operators :

* Include input features that touch the selection features
* Include input features that overlap/cross the selection features
* Include input features completely within the selection features

Which can be combined in a binary OR manner.


What about exposing each existing geometry operators supported by
QgsGeometry class :

* intersect
* contains
* disjoin
* equals
* touch
* overlap
* within
* crosses


Arnaud