Use kbpgp in a webworker

[acasajus]

I need to use kgpgp in a webworker. When I try to do so I get

No rng found; tried requiring "crypto" and window.crypto

since there's no window global defined, but there's self.crypto. I'm using kbpgp via browserify, any tips on how can I make kbpgp use self instead of window?

[acasajus]

Seems to be the same as #90