The way I was filtering out entries in the frameworks array stopped
working in newer versions of ZSH; it would convert the array into a
string (you could see it with `typeset -p frameworks`)
So I rewrote it.
I don't see anything in the release notes for ZSH that would explain
this and I didn't find any option that would restore this behavior.
Related: #882
This adds `./test-in-docker` for quickly playing with various frameworks.
All the containers are based off Ubuntu 14.04 which has ZSH 5.0.2.
Thanks to @dritter for figuring out all the framework installation
methods.
