fix is_subscribed_to()
rename DeleteTrailingSpaces.py to coding_std.py

--HG--
rename : contrib/pep8/DeleteTrailingSpaces.py => contrib/pep8/coding_std.py
simplified output status messages, corrected one message
fix #379 quickinstall.py fails with obscure error message
workaround for #385 RunTimeError: working outside of application context (pdfminer == 20131113)
fix #379 part 2, replace traceback with error message