[gtkmm] error compiling examples with the 2.0.0 release

["xavier dufresne" <xdufresne gmx fr>]

3 example sources produced an error while compiling on my system because the
'#include <iostream>' directive is omitted:
gtkmm-2.0.0/examples/book/box/examplewindow.cc
gtkmm-2.0.0/examples/book/box/main.cc
gtkmm-2.0.0/examples/book/table/examplewindow.cc

I never had this problem with previous versions of gtkmm2.

My system: redhat 8.0, gcc 3.2

xavier

PS: I attached a patch

Attachment: gtkmm.diff.gz
Description: GNU Zip compressed data