Add a command to be able to assign an issue to a certain milestone

[rogaha]

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[crosbymichael]

Milestones should be a separate binary. ;)

This will allow us to do things like issues --today | milestones --add do batch operations and such

[rogaha]

I really think that we should keep the implementation modular, as it's with multiple binaries sharing the same core, but it's very important to be easy to use. In my opinion there should be a layer on the top (gordon?) to centralize all the features available! :)