In version 2.6, new keywords has been added to Expression :
* $currentfeature - returns the current feature
* $atlasfeature - returns the atlas feature
* getFeature - gets a matching feature from a layer
But I think, Expression lacks a few keywords :
* geometry - returns the feature's geometry
* transform - returns the transformed geometry
These new keywords can be used with getFeature for some geometry tests like
intersects, crosses, contains, etc
Tests has been added to geometry and transform in Expression
