This Exception can be thrown whenever a sync error occurs. It is used
for outputting sensible error messages to the user and it denotes a
"severity", it can tell offlineimap if we need to abort a message, a
folder, a repo sync, or whether we should indeed abort immediately.
The exception is not yet used in the code.
Signed-off-by: Sebastian Spaeth <Sebastian@SSpaeth.de>
Signed-off-by: Nicolas Sebrecht <nicolas.s-dev@laposte.net>
