Peter M. Groen / oletools

Before using log_helper in olevba logged a "finalization message", which is
no longer required. Had forgotten to update unittests.

On my test VM this reduces test time for this one test from 33s to
10s

VBA stomping warning might occur here

Do not need the last meta-information return code json output from
olevba any more

Running main() within same interpreter capturing SystemExit and
sys.stdout/err always causes trouble (at least in unittest).
Fork another python process and capture from there, that is easier
and cleaner in my view.

This is an interesting one since "our" old implementation of is_encrypted
claims that the embedded file is still encrypted (which it is not), but
the msoffcrypto-is_encrypted gets it right.

These are encrypted with the standard password hard-coded into excel to
implement a form of write protection