Added feature info control for Vector layers.

Now we can display the Vector layers features
attributes in a popup dialog, pretty much like
the wms ones.
Please note the control is not full-featured
yet, so it doesn't format the output or work
with mouse hovering yet. Also, it's almost
useless with non-polygon features as of now.
Added a small legend to the custom layer switcher.

Now alongside each Vector layer a small box with its
fill color (stroke color is ignored) is drawn. Had to
made a few changes in dynatree, and thus I'm uploading
new versions for both the debug and minified format.