Xin Sun authored Dec 21, 2013 and Tiago Peixoto committed Dec 21, 2013

In case google sparsehash uses a non-standard prefix, e.g., in Homebrew.

The routine wrongly returned 1/lambda instead of lambda, as the leading
eigenvalue of the adjacency matrix.

This reduces memory use during compilation.

This makes edge deletion O(1) if fast edge deletion is enabled for the
graph.

This enables the acceptance of numpy types such as numpy.int64 as
parameters to functions taking C++ integers or floats.

This also includes a "mid_marker_pos" edge attribute which allows a
relative placement of the mid marker along the edge.