kaitaiStructCompile.py CLI backend

This is a CLI backend for kaitaiStructCompile.py.

Cons:

• insecure: uses subprocess.call, passes arguments via a command line; also races on access to files are possible: if an attacker wrote the temporary file between ksc have it unlocked and the app have not yet read, he can replace the file contents. If importer is used, it is code execution and injection attack.
• slow: creates subprocesses, interacts via on-disk files and stdout;
• burns in SSD - since it uses temporary files.

Pros:

• universal - should work on any OS
• requires no dependencies
• permissive license