F19 upgrade ICU to 50.1.1 in sync with Boost upgrade

[Eike Rathke]

Hi,

I plan to upgrade ICU to version 50.1.1, best next week to have that
ready before the Boost upgrade will happen to avoid having to rebuild
the entire chain twice. So don't get overly alarmed by broken
dependencies of other packages.. but still fix them in time for the
Boost upgrade.

Thanks
  Eike