A feature request (2/4): import/export of the boards

[thread13]

Since apparently this project had some recent attention -- I wonder if it would be possible to backport some nice features from other forks, for example porting boards between servers via manual import/export ; it is also nice to allow the users to save their data independently.

A reference implementation: stevemoreau/scrumblr.

[gerhardbeck]

think this is very necessary for backup reasons