add boost::generator_iterator_policies and convenience classes

[SVN r11725]
add generator iterator adaptor

[SVN r11736]
fix example (thanks to Michael Stevens)

[SVN r11979]
Fix from Yitzhak Sapir <yitzhaks@actimize.com>

[SVN r16198]
add or update See www.boost.org comments

[SVN r16708]
Move to new iterator adaptors

[SVN r19074]
Removed access category tags from iterator library, made corresponding changes elsewhere.

boost/iterator and libs/iterator/test were updated from
branch "simplify"

[SVN r20905]
Converted to Boost Software License, Version 1.0

[SVN r24055]
c++boost.gif -> boost.png replacement

[SVN r25573]
Fix broken links

[SVN r30403]
Fixed license & copyright issues and converted to HTML 4.01

[SVN r36280]
Link to people pages on the website, as they've been removed from the download.

[SVN r43209]
Use a local copy of the valid HTML 4.01 icon.

[SVN r53048]
Added test for generator_iterator.hpp.
Move generator_iterator doc/test files, update test/Jamfile.v2.