Implement App data management to API

Add support to Reset App storage via API and Info Page
changed to data_folder which is used as variable on application_info.py
Update CHANGELOG

Author: tlindi

rootfs/standard/var/www/mynode/api.py

@@ -149,7 +149,6 @@ def api_restart_app():
 
     return "OK"
 
-#    @mynode_api.route("/api/restart_app")
 @mynode_api.route("/api/backup_data_folder")
 def api_backup_data_folder():
     check_logged_in()