History loading limit is needed as a configurable option
On reconnect the history is fully loaded without any limit, which is a relatively slow process and becomes a real problem if some gajim client was absent from network for a sufficiently long period of time, like a week or a month.
This affects me personally and a couple of my friends: for example, I boot into another OS on my machine approximately once or twice in a month and every time I have to wait several minutes seeing a flood of history messages and notifications from all chats, having gajim totally unusable during that time. An other example would be opening gajim client at work for the first time after the weekends - it takes a minute approximately, before the messages & notifications flood ends.
So, I suggest introducing an option that makes users able to control the size of automatically loaded history, in hours or days, maybe.