Tooltips for nodes

[MathemanFlo]

In my opionion ArmorPaint is already very intuitive to use. But I think especially some nodes are maybe not so intuitive to use, for instance the Geometry node or the Texture coordinate node or what "use_clamp" actually means. The best documentation is always a explanatory program itself because one needn't look elsewhere. Therefore it would be nice to be able to add tooltips for sockets and controls in nodes to be able to add some explanatory text.