PATCH (head): -Wunused-static-variable

[Kean Johnston]

> I am with Neil Booth on the -Wall issue. After all, the new 
> warning _is_ correct and provides useful functionality, so it
> should be on by default. Those who are stuck with legacy source
> trees should be able to come with necessary Makefile changes
> order of magnitude easier that with the necessity to modify
> each and every source file in the tree.
In my case, I would *only* have to change 4009 makefiles. That's
in tree 1 of 3. The others are similarly sized. Well Id have to
change them *IF* I was affected by this, which personally I am
not, but I can see many many cases where people will be.

Kean