Toolset tweaks

Here are some tweaks that allow integrated toolset to be used where it should be:

1. Allows to butcher with a toolset 
2. Reload ammo with heat from toolset (why would it need to be hotplate only?)
3. Using toolset as welder for making steel platings
4. This one I'm not sure about, but it seems to be reasonable: cooking drains toolset MUCH more then it would drain batteries on a hotplate (100 batteries equivalent versus 7 with a hotplate). This patch sets it to equivalent of 25 batteries which is still a lot.