Fixed broken geometry limit input.

Now it ACTUALLY CHANGES the amount of geometries on the map, and the use of a
custom function to be enqueued in the call object provides the illusion of
making real good sense!!!
For now I just invalidated all the 'pads' (what a stupid name) but this could
be fine-tuned a bit.
Intercepted filter commands during initialization.

T'is the small joys that make me want to live on to the next day:
If someone for instance clicks on a type checkbox during the one or two seconds
of page load, the command is stacked onto filter_documents.commands instead of
being processed right away. filter_documents(filter_documents.commands)
triggers execution of those as soon as document-geometry associations finished
loading.
Also this will build the geometry key list from filters[0].documents, so this
part isn't written twice anymore.
'Refactored' initialization of filters[0].documents.

That is, changed to backwards iteration to aviod array re-hashes, and it made
no sense to use 'keys' for this.