Allow alternative distribution names

[assignUser]

• bernoulli as "standard" alternative to binary
• gaussian as "standard" alternative to normal

[assignUser]

I am not sure about this one, there is quite a bit of code dependent on the names other than just the generate stuff, so there is a large potential for introducing errors now and down the line.

Maybe a better approach would be to add the names to the documentation That is already the case with the new overview vignette.

Let me know what you think.

[kgoldfeld]

I am not saying this is the most crucial thing, but what if we just added two new distributions that happen to act just like two existing distributions? So, we wouldn't break anything internally.

[assignUser]

that would not really change anything^^
The issue is not with integrating the new distribution names in the generate chain, that's rather easy. But there are a quite a few checks like this spread around that we would also need to adjust:

[kgoldfeld]

But what if I said we want to introduce a new distribution, say the Weibull distribution - would you make the same argument?

[assignUser]

In a way you are right, I will check out what the dependencies are exactly and think about how to best proceed.

[assignUser]

This is another issue that would benefit from the switch to r-expressions #75 as these dependencies I mention here would basically all go away,