Updating waf to 1.6

[Kevin Kofler]

Simo Sorce wrote:
> You are free to volunteer to do that, I am not going to do it for
> samba4, I simply do not have the time to waste on such a thing.
> (Samba4 people are in strict contact with the waf author and use
> regularly the svn version du jour to fix build bugs they found, good
> luck trying to make samba4 build right with months old releases that do
> not include all necessary fixes).

I think the cleaner approach would actually be to aggressively update waf 
and to fix projects to build with a newer waf, not an older one.

But once we have working waf-using Samba4 releases, making things build with 
an older waf will probably be as easy as reverting some commits. (I've done 
"old-libfoo" hacks on some occasions, usually it's just "find the offending 
upstream commits and revert them".)

        Kevin Kofler