Changes:
* Reduce the Zim "core" to a single file
* Simplify installation with an installation script (Closes#182)
* Put the configuration into .zshrc instead of a separate .zimrc
(Closes#288)
* Do not support themes that require promptinit (See #325)
* Generate a static script that does autoload the functions and source
the modules
This version is not backwards-compatible with previous versions, so a
new installation of Zim is required.
