Add delete_memoized and delete_cached functions to clean cache
Add delete_memoized and delete_cached functions to clean cache

inteligencia-coletiva-lsd/pybossa,CulturePlex/pybossa,geotagx/pybossa,CulturePlex/pybossa,proyectos-analizo-info/pybossa-analizo-info,Scifabric/pybossa,geotagx/pybossa,proyectos-analizo-info/pybossa-analizo-info,geotagx/geotagx-pybossa-archive,OpenNewsLabs/pybossa,jean/pybossa,Scifabric/pybossa,inteligencia-coletiva-lsd/pybossa,jean/pybossa,stefanhahmann/pybossa,geotagx/geotagx-pybossa-archive,proyectos-analizo-info/pybossa-analizo-info,geotagx/geotagx-pybossa-archive,stefanhahmann/pybossa,CulturePlex/pybossa,harihpr/tweetclickers,harihpr/tweetclickers,geotagx/geotagx-pybossa-archive,PyBossa/pybossa,OpenNewsLabs/pybossa,PyBossa/pybossa,geotagx/geotagx-pybossa-archive