It just includes a bunch of other boost headers; mostly we need
boost/noncopyable.hpp so include that directly.
This eliminates 831 MB(!) of boost/preprocessor/seq/fold_left.hpp
completely, which is the 2nd biggest header after ustring.hxx.
Change-Id: I3df55770adcb46e56f389af828e8ba80da2dc1f2
7aa9f04538