Ensure in/out_edge/adjacency_iterator and associated are random access in adj_ist<> and UndirectedAdaptor<>

This enables the inclusion of the non-boost tr1 headers if a recent
enough version of libstdc++ is detected. This als fixes a bug with
clang when sparsehash pulls unwanted tr1 headers.

The object may be globally reset via the seed_rng() function.

This install the boost workaround headers together with graph_tool's
header files.

This includes a spirit parser for the gml syntax, and a graph writer.

Additionaly, the general graph io code also been cleaned up.

Now properties can be copied from vertices which are not identical
(e.g. from unfiltered to filtered graphs, etc). This fixes a problem
with graph copying and pruning, where the properties were not correclty
copied.

This removes reverse_graph.hpp, reverse_graph.hpp and copy.hpp, and
introduces some modifications in graph_adaptor.hh. This modification
fixes compilation problems across different boost versions.

This module contains several search algorithms and a visitor interface.

This also maintains compatibility with older boost versions.

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 implements a layout module (called 'draw' from python) with an
implementation of the arf spring-block layout.

This includes the edmonds karp, push relabel and kolmogorov maximum flow
algorithms from the BGL.

This adds the centrality module, which supports betweenness, eigentrust,
pagerank and absolute trust.

Now inline() automatically converts known variables (such as property
maps) and defaults to boost::python objects, instead of scxx objects.

The code now is only generated for the current filtered, reversed and/or
directed status of the graph, reducing compile time and binary size.

Edge modification (remove and add) is now protected by a GraphWrap
class, which takes care of the edge index housekeeping, which does not
need to be done by hand anymore.

The function is also no longer bound to one graph, and can take an
arbitrary number of variables of known or unknown types, including
graphs.

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.

This includes the community sub-module.

This also creates the misc sub-module. This may be re-organized in the
future.

This contains at the moment functions to perform basic vertex and edge
searches.

Add $(srcdir) to include paths in AM_CPPFLAGS so that we can
compile the program writing all targets into a directory separate
from the sources.
This is done simply by creatig a subdirectory of the project root
and running "../configure" and "make" inside it.

A new 'clustering' sub-module was created.

The whole histogram code has been redone, and the code has been
simplified. The three-point vertex-edge-vertex correlation has been
scrapped, since it's not frequently used, and would make compilation
even more expensive.

This also adds some missing files to the generation routine.