changes since 1.8.8
 * Python 3 now supported.
 * allow 'EPSG' init (as well as 'epsg'). This only worked on case-insensitive
   filesystems previously. Fixes issue 6.
 * added inverse to Hammer projection.
 * updated src/pj_mutex.c from proj4 svn to fix a threading issue on windows
   (issue 25). Windows binary installers updated (version 1.8.8-1), courtesy
   Christoph Gohlke.
 * if inputs are NaNs, return huge number (1.e30).
1.8.8 (svn revision 196)
 * add extra datum shift files, added test/test_datum.py (fixes issue 22).
   datum shifts now work correctly in transform function.
1.8.7 (svn revision 175)
 * reverted pj_init.c to old version (from proj4 4.6.1) because version in
   4.7.0 includes caching code that can cause segfaults in pyproj (issue 19).
 * added 'preserve_units' keyword to Proj.__init__ to suppress conversion
   to meters.
1.8.6 (svn revision 169)
 * now works with ms vs2008, vs2003 (fixed missing isnan).
 * updated to proj 4.7.0 (fixes a problem coexisting with pyqt).
 * allow Geod instance to be initialized using a proj4 string 
1.8.5 (svn revision 155)
 * allow Proj instance to be initialized using a proj4 string 
   (instead of just a dict or kwargs).
1.8.4 (svn revision 151)
 * updated proj4 sources to version 4.6.0
1.8.3 (svn revision 146):
 * fixed bug in Geod class that caused erroneous error message
   "undefined inverse geodesic (may be an antipodal point)".
 * fix __reduce__ method of Geod class so instances can be pickled.
 * make sure points outside projection limb are set to 1.e30 on inverse
   transform (if errcheck=False).
 * fixed small setup.py bug.
 * generate C source with Cython 0.9.6.6 (pycompat.h no longer needed).
1.8.2:
 * added 'srs' (spatial reference system) instance variable to Proj.
 * instead of returning HUGE_VAL (usually 'inf') when projection not defined
   and errcheck=False, return 1.e30.
 * added Geod class for geodesic (i.e. Great Circle) computations.
   Includes doctests (which can be run with pyproj.test()).
 * proj.4 source code now included, thus removing proj.4 lib
   dependency. Version 4.5.0 is included, with a patch to
   create an API for geodesic computations.
 * python 2.4 compatibility patch (suggested by Andrew Straw) 
   from M. v. Loewis:
   http://mail.python.org/pipermail/python-dev/2006-March/062561.html 
1.8.1: 
 * if given tuples, returns tuples (instead of lists).
 * test for numpy arrays first.
 * Fixed error in docstring example.
 * README.html contains html docstrings generated by pydoc.
 * Renamed pyproj.so to _pyproj.so, created a new python module
   called pyproj.py.  Moved as code as possible from _pyproj.so to
   pyproj.py.
 * docstring examples now executed by doctest when 'pyproj.test()' is run.
 * added test to _pyproj.c which defines Py_ssize_t for python < 2.5. 
   This is necessary when pyrex 0.9.5 is used.
1.8.0: 
 * Better error handling Proj.__init__.
 * Added optional keyword 'errcheck' to __call__ method. 
 * If True, an exception is raised if the transformation is invalid.
1.7.3: 
 * python 2.5 support.
