Bugfix: several occurrances of repo_name in .py files where it should be app_name; and for short_description, triple quote is safer

In conf.py and setup.py, there are several occurrances of repo_n...ame where it should be app_name. Also, in the short description, there may occur a single quote, which messes up the single quoted short-description string; better enclose that string with triple-quotes (those are a lot less likely to occur).