document and fragment allow conditionals and nested arrays of filter&transformer pairs

[da-z]

Hi Anthony. First, let me thank you for this great library.

I just started to use it a few days ago and found that I needed more flexibility when defining my fragment and document bodies, so I made those modifications.

Maybe you find the feature useful enough to add it into the main branch.

Regards

[Raynes]

This is a great idea. I've merged your pull request, but I made some changes that I'll go over briefly:

• ffns wasn't a very descriptive name so I renamed it to flatten-fns.
• I don't care for the clojure.core/flatten function. It completely ignores maps! While that isn't a problem for our particular use-case, we already had an improved version we wrote for clojail so I just put that in useful and used it here instead. You didn't do anything wrong here though, it's just my OCD kicking in ;).
• The formatting of the test you added was really bad. This was the only thing you did that I really needed to change. Clojurians almost never put brackets on their own lines like this (as you might be familiar with from languages like C, Java, and C#). It makes it nearly impossible to read for other Clojurians. It may seem better at first, but it really isn't. Always inline those brackets. You can see how I did it in the commits I added in master.

Overall, good work and thanks for the contribution. I was trying to think of the best way to do this sort of thing and I think your way is really good. I've released a new version 0.1.28 if you want to start using it right away.

[da-z]

Awesome! Grateful for all the tips too.