Fix variants, add tests

[mvduin]

They were apparently quite broken...

before:

> unmarshall(marshall("vv", [ ['i', 42], ['s', 'foo'] ]), "vv")
[ [ [ [Object] ], [ 42 ] ], [ [ [Object] ], [ 'foo' ] ] ]

> unmarshall(marshall("v", [ ['ai', [1, 2, 3]] ]), "v")
Error: Invalid struct data

after:

> unmarshall(marshall("vv", [ ['i', 42], ['s', 'foo'] ]), "vv")
[ [ 'i', 42 ], [ 's', 'foo' ] ]

> unmarshall(marshall("v", [ ['ai', [1, 2, 3]] ]), "v")
[ [ 'ai', [ 1, 2, 3 ] ] ]

[sidorares]

Thanks Matthijs , I really hope to find time soon to review all pending PRs on this project, was very very busy lately

[mvduin]

Just letting you know that I no longer care about this PR. I wrote my own dbus module instead.

[sidorares]

@mvduin Sorry to hear that. I'm happy to add link to your module from readme here

[ghost]

@sidorares : can this be merged if the conflict is resolved? This is helpful for eslint, so I'd like to merge it before prettifying.

[ghost]

So obviously that didn't happen, but I'd still like to see a fix for variants. Can you review it @sidorares

[ghost]

@sidorares : so how about this one?