Merge pull request #107 from KellyBlack/bugfix_create_temp_data_file

Fixed bug in how the files used to keep temporary data files are created...
Adding the same README.md that we use for webwork2 to the pg page.
Final edits to readme.
Merge pull request #132 from goehle/newreadme

Newreadme - Release/2.9
Merge branch 'release/2.9' of https://github.com/openwebwork/pg into develop