to phat commit. see extended description

* introduces PinTypes
* drops VVVV.Core.WebGlResourceNode; uses
VVVV.PinTypes.WebGlResource instead
* fixes bug where equally named in-
and output-pins where mixed up
* adds "Node" IOBox category
* makes
Node.findDownstreamNodes work across subpatches
* adds support for
multiple, named connection changed handlers
* makes dirty and
auto_evaluate flags propagate across multiple subpatch levels
* fixes
Node.getSubpatches
* adds IOBox (Node)
fixes non-working value initialization with default value in Pin.setType
introduces VVVV.PinTypes.Transform; uses it in WebGL and Canvas nodes
adds missing (Node) category file