SBCL uses installer on Windows instead of zip

[asmaloney]

On macOS and Linux, the setup script downloads the latest Steel Bank Common Lisp and installs it in our virtual environment.

It looks like the Windows version is only provided as an installer (.msi), so ti doesn't fit with this workflow.

I don't know the best way to handle this. Maybe let the user install it system-wide using the installer and then look for it in the scripts?

These are the instructions for installing on the command line which will need to be modified for Windows:

1. Download the correct version from here by finding your platform (OS and architecture) in the table and clicking its box. Put the file in the env directory and unpack it there.

2. To install it in our environment, change to the new directory it created (e.g. sbcl-1.2.11-x86-64-darwin) and run this command (setting the path to wherever the env directory is):

   INSTALL_ROOT=/path/to/gactar/env/ ./install.sh

3. Once it is successfully installed, go back to the 'env' directory and run the following command to compile the main actr files using the Lisp compiler (setting the path to wherever the env directory is):

   export SBCL_HOME=/path/to/env/lib/sbcl; sbcl --script actr/load-single-threaded-act-r.lisp

   This will take a few moments to compile all the ACT-R files so it is ready to use.

[asmaloney]

No longer applies.

Switched to Clozure Common Lisp compiler in fbf81b8.