[MapQuery] Must read before code sprint

[Volker Mische]

Hi all,

the code sprint in Amsterdam comes closer. I guess (and hope) it will
solidify the MapQuery API. It has gone to many changes. For example
.layer() previously had a signature like:

  .layer(id, options)

I then switched (proposed by Drew iirc) to

  .layer(options)

I'd like to switch back again. My reasoning was this great article about
arguments in JavaScript functions:
http://blog.rebeccamurphey.com/objects-as-arguments-in-javascript-where-do-y

Please take your time and read through it, it's really worth it (even if
you are not attending). I think for MapQuery I'd like to go mostly the
"Use Objects for Related Data" path. In the case mentioned above I see
the ID independent of the layer options.

We should also look at other libraries to see what they are doing.

Cheers,
  Volker