Support PyInstaller .exe files

[dwvisser]

PyInstaller .exe files gather together the relevant python interpreter and all needed libraries to create a Windows executable that doesn't require the end user to have Python separately installed on their system.

This issue is somewhat related to #307, in that PyInstaller files contain .pyz archives. The PyInstaller Exctractor project shows how to extract the contents of the PyInstaller file.

PyInstaller files never contain source code, i.e., only .pyc and .pyo files. See, e.g., the PyInstaller manual. This means it would be necessary to invoke a disassembler or decompiler for analysis.