Python: A simple Precertificates finder

Also fix the scanner code to provide the matcher function with the
actual precertificate rather than the precertificate's signer.
Fix two cases of using the wrong delete.
Fix a make error when there is no *.pyc files.

When there is no *.pyc to delete, GNU xargs will still run the command once
with no arguments, which causes an error, stopping make. The -r flag prevents
this.
Python: Adding Golomb coding for EV whitelist.
Python: EV certs whitelist generation utility.

Use the scanner to identify and fingerprint all certificates with
an EV policy OID that chain to the correct root for thin policy.