Fix breakage due to CSP changes

The Apache CSP changed so that we can't load any
scripts, fonts, or images from other URLs.
Therefore all the ones we currently use have to be
put here so they're loaded from the same domain.
Also fix some Jekyll URL templating so that
_config_dev.yml can work properly with modern
Jekyll verisons.

Change-Id:If17ec8dbd1de435c9a0c6edf4dab71e6ede2a5a3
Reviewed-on: https://asterix-gerrit.ics.uci.edu/c/incubator-asterixdb-site/+/19508
Reviewed-by: Ian Maxon <imaxon@apache.org>
33 files changed