Create simple non-thread-safe "gasname()" function

[Dirk Hohndel]

On Sun, Jun 01, 2014 at 06:25:44PM -0700, Linus Torvalds wrote:
> 
> Every single user of the get_gas_name() function wanted to just use the 
> result to create a message or printout, and that made the interface a bit 
> cumbersome.

Thanks for doing that. It was on my todo list. I think I'm making progress
wrt the gasmix conversion. Of course I should do the same for depth as
well...

This didn't apply cleanly as I had made a couple more changes since the
version that you started from, but I believe that I correctly merged
everything.

/D