cross compiling with --cross-answers in waf

[tridge at samba.org]

Hi Simo and George,

I've now added the --cross-answers option for cross compilation to the
waf build, as I described earlier. This means we can cross compile
accurately without having a target emulator on the host.

There is documentation here:

  http://wiki.samba.org/index.php/Waf#cross-compiling

Please give it a try and let me know if it works OK in your
environment.

Cheers, Tridge