History support

[vaygr]

It seems it's not done by default, and entry.save_history() has to be called explicitly in pykeepass.

Even just saving could be a good start, but in the future access to previous versions would be great.

[firecat53]

Add the save feature would definitely be a good and easy add. I'll have to think about whether the complexity of accessing history in keepmenu would be worth it.