Grid and property layer for hexgrid

[quaquel]

#2430 adds support for plotting hexgrids. It comes with an optional grid using a patchcollection. This results in some overdrawing of lines wich is less than ideal.

Also, property layers won't display correctly yet because the coordinate systems are different.

The solution to both might be to create a polycollection (as used in matplotlib's hexbin).

[Sahil-Chhoker]

I am reading this issue now that I have opened a PR(#2609) for the fix of hex-grid overlapping, do you think I should have used PolyCollection instead of LineCollection?
Also I would like to work on the property layer issue as well, any pointers before I start working on that?

[quaquel]

Not sure. Conceptually, the grid drawing and the property layers drawing can use distinct datastructures. Implementation-wise, they are distinct methods, so it might be easier to merge #2609 first and iterate back to it after addressing the property layer drawing.