multiple fixes: switched file tracking to a two file based system so repeated calls to get_new will return the same set of files. Replaced equivalent code in init with a call to refresh(). Changed behavior of _store, file list only written if there are changes. Changed _load, added option to load previous set of files. Changed get_new to work with these changes.
multiple fixes: switched file tracking to a two file based system so repeated calls to get_new will return the same set of files.
Replaced equivalent code in init with a call to refresh().
Changed behavior of _store, file list only written if there are changes.
Changed _load, added option to load previous set of files.
Changed get_new to work with these changes.

aburrell/pysat,jklenzing/pysat,rstoneback/pysat