Add logging on IOError for Image and Album thumbnails

For sorl-thumbnail and imagestore it is not uncommon to have issues with file handling, media paths, etc. 

On my installation I setup a logging handler by adding the following at the end of settings.py. I don't know if this is essential. :

LOGGING = {
    'version': 1,
    'disable_existing_loggers': False,
    'formatters': {
        'verbose': {
            'format' : "[%(asctime)s] %(levelname)s [%(name)s:%(lineno)s] %(message)s",
            'datefmt' : "%d/%b/%Y %H:%M:%S"
        },
        'simple': {
            'format': '%(levelname)s %(message)s'
        },
    },
    'handlers': {
        'file': {
            'level': 'DEBUG',
            'class': 'logging.FileHandler',
            'filename': os.path.join(LOG_DIR, 'mysite.log'),
            'formatter': 'verbose'
        },
        'imagestore_file': {
            'level': 'DEBUG',
            'class': 'logging.FileHandler',
            'filename': os.path.join(LOG_DIR, 'imagestore.log'),
            'formatter': 'verbose'
        },
    },
    'loggers': {
        'django': {
            'handlers':['file'],
            'propagate': True,
            'level':'DEBUG',
        },
        'imagestore': {
            'handlers':['imagestore_file'],
            'propagate': True,
            'level':'DEBUG',
        },
    }
}