This is a very simple, small patch that merely moves the Tweak tool to the transform section in the toolbar:
Motivation:
The primary purpose of the Tweak tool is to be able to quickly transform items without needing to select them first. The Tweak tool essentially allows selection and transform in one step.
One could argue both ways, but in my estimation it should be thought of more as a transform tool than a selection tool. There is no reason to enable this tool for any kind of selection - it is only useful for quick successive transforms.
This patch also removes the Tweak tool from the node editors, since it has no useful purpose there.