Patch: stl_vector.h

[Paolo Carlini]

Paolo Carlini wrote:

> Therefore, it seems to me, that we should definitely add "casts" also 
> at that
> level, not only at the level of the containers... The latter is 
> bigger, but would
> stay also after the resolution of 438.

Sorry, I really wanted to say: the former change is smaller (that 
affecting the
specialized algorithms, that is an additional _Construct taking an 
allocator and
"casting" as the existing one do) and would stay after the resolution of 
438.

Paolo.