With this change, hit detection for lines and points gets very
accurate, because the vector renderer instance keeps track of
line widths and point symbol sizes. After doing a bbox query in
the RTree, returned lines and points are evaluated against the
thresholds of their line width or symbol size. The KML example
with its different symbolizers now has getFeatureInfo too to
show this in action.
Rendering vector tiles with mixed geometry types does not work
as expected, because the tile is created without the geometries
that need another rendering pass because of missing icons. This
was discovered by @bartvde when working on the KML parser, where
mixed geometry types are common.
This change fixes the issue by breaking out from rendering
entirely when renderFeaturesByGeometryType returns a deferred
state. In addition, there was a related bug because icons are
added to the cache regardless of its loaded state. This is also
fixed now.
