Blender Git Loki

Codesign: Make Windows codesign check more strict

Check that signtool reported number of files successfulyl signed,
and that the number equals to 1.

Codesign: Report signing errors on Windows

Merge branch 'master' into codesign_error_tracker

Codesign: Report codesign errors from server to worker

Pass codesign errors (if any) from codesign buildbot server to the
buildbot worker, so that the latter one can abort build process if
the error happens. This solves issues when non-properly-notarized
DMG package gets uploaded to the buildbot website.

This is an initial pass of implementation tested on Linux. Other
platforms requires to have proper testing.