Description: install doc in the right place for Debian

diff -Naurp networkx-1.8.1.orig/setup.py networkx-1.8.1/setup.py
--- networkx-1.8.1.orig/setup.py	2013-08-04 09:53:31.000000000 -0400
+++ networkx-1.8.1/setup.py	2013-12-19 09:22:45.510371904 -0500
@@ -62,7 +62,7 @@ if sys.version >= '3':
 else:
     packages.append('networkx.external.decorator.decorator2')
 
-docdirbase  = 'share/doc/networkx-%s' % version
+docdirbase  = 'share/doc/python-networkx'
 # add basic documentation 
 data = [(docdirbase, glob("*.txt"))]
 # add examples
