proposal: merge waf build of s4 to master

[tridge at samba.org]

Hi Kai,

 > I've also played with cross-compiling Samba (both 3 and 4) to the Android 
 > platform recently, but both of them stubbornly resisted my attempts so far, so 
 > I didn't even think about looking at waf for that.

I think we just need to get dpkg-cross to convert the native ARM
packages to cross-packages. Then they should install in
/usr/arm-linux-gnu and the waf build of s4 should work fine (following
the steps I put on the wiki page).

dpkg-cross is a bit of a monster though. It seems to really want a
debian system, as it keeps trying to install from 'unstable' and the
-S option to override doesn't seem to work for -i.

Maybe Simo has a better cross compilation env on Fedora? Simo, do you
want to try building s4 cross-compiled on ARM?

Cheers, Tridge