Use SOLID_TRIGGER instead of SOLID_NOT for attachments or non-solid object. This...

Use SOLID_TRIGGER instead of SOLID_NOT for attachments or non-solid object. This seems to make grabbing non-solid sandbox objects possible, although the dragging itself is based on trace_ent so I don't understand how this can be (given neither SOLID_NOT or SOLID_TRIGGER can get traced, so it shouldn't make a difference). This seems to work though, so I guess it's good SOLID_TRIGGER should also be better for possible changes that might get done in the future.