Dumping boost::adjacency_list<> improves memory usage by a factor of
two, and also slightly improves performance in some cases.

This allows compilation with older versions of boost (>=1.38), which in
some sistems are the only option. This commit also removes the linking
of the boost_graph shared library, since none of its symbols are
actually required.

Fix compilation warnings with boost 1.40, remove unnecessary files, fix
autoconf macros and link with "boost_graph".

This also raises the minimum boost version to 1.40.

This makes the naming more sensible.

This includes a new vector property map type (fast_vector_property_map)
which has optional disabling of bounds checking, through its associate
map type (unchecked_fast_vector_property_map). This should improve
performance on algorithms which depend on tight loops which access
property maps.

Bounds checking is only disabled locally just before the algorithms run,
and proper care is taken for bounds checking _beforehand_. The property
maps exposed to python still have internal bounds checking.