Install obspy using cygwin fails

see http://stackoverflow.com/questions/21853678/install-obspy-in-cygwin
and a proposed fix http://sourceforge.net/p/cygwin-ports/python-obspy/ci/master/tree/0.9.0-cygwin.patch

however I would probably simplify the patch by just removing special chars from the library names using a simple function, e.g. ```clean_filename(filename)```  ...