change catching exception style in sphinxext/inheritance_diagram.py
use sphinx.ext.inheritance_diagram instead of sphinxext/inheritance_diagram.py
use sphinx.ext.inherit_diagram instead of given one.
apply print function on sphinxext/numpydoc.py
use print_function on sphinxext/apigen.py and sphinxext/docscrape.py
new file:   .gitignore
change catching exception style in sphinxext/docscrape.py
remove import StringIO from sphinxext/docscrape.py (not used)
modifile warning extensions.rst when newline is inserted in inline math
directive.