2019.04.26
Moved Windows-specific code from src/cluster.c to windows/library.c.
Fixed a memory leak in X11/gui.c.
Expanded doctests in python/__init__.py.
Fixed a bug in the treecluster routine in python/clustermodule.c that caused
the weight argument to be checked if the distance matrix was provided.
Cleaned up formatting in python/test/test_Cluster.py.
