Implement "Points of Interest" table

[kkmcgg]

We could benefit from a clean and clear way to tracking certain 'points of interest' - specific locations where we may like to test our models repeatedly. Currently, out getTile() can accept either tile coordinates integers, or lat/lon float values. We could design this function to accept strings as well whereby we provide a list of specific strings which relate to a list of coordinates.

for example: the Eiffel tower is at 48.8584° N, 2.2945° E

we can create a lookup table dictionary such that:

{'eiffel' : [2.2945,48.8584]}

which should give get tile the following functionality:

core.getTile('eiffel', show=true)

Implement a system which can acceive the above funcatinaity in the core.getTile() function. Consider: how could we incorporate both a default zoom level for a given POI and also the ability to use various zoom levels for a given AOI when calling getTile()

Once built, feel free to add some points of interest of your own!

[ghost]

Added initial functionality for this. Haven't integrated it with the classic getTile functions yet, though.