add otpauth url import export support

[Sneezry]

#282

made changes

[nmarley]

@mymindstorm I really don't like this new format as it doesn't work with my established workflow. Is there any way to opt to use the old JSON format export?

[mymindstorm]

@nmarley it should use both just fine. It tries to detect which format you use.

[nmarley]

Thanks. I really just mean I prefer to manage my backups using the JSON format. But I've found a way to just keep adding to the JSON format one for "backups" / imports.

Cheers,