Backup/restore configuration

[bkhl]

Since I use the app on more than one phone, I've found myself needing to manually change a bunch of config to match my preferences. If I make some change, I tend to end up with mismatching config on different phones and getting disorientated.

It would have been handy if there was a way to dump/restore the application config to a file.

[romariorobby]

Yeah, i do the same. For now, i just backup search queries. but backup whole orgzly config would be helpful.

[xiaoruoruo]

I think this is dupe of #156