Feature/bindtointersection
This MR adds a bind(intersection,side)
method to the local function interface. The method has a default implementation based on the standard bind(entity)
method. In ConstLocalFunction
some SFINAE magic is added to switch between an existing implementation on the grid function and using the default.
I'm using this in the integrands
model to allow for functions defined only on give intersections and will also add it to the dirichlet bc class.