Modify `CMD` and `ONBUILD CMD` to `chmod 755` everything

Many different Spoke, Admin, Maintenence and Worker containers need to
be able to at least view the configuration files in the Hub container.
And even with Spoke containers alone, it is impossible to guess what the
name of the user will be that will eventually use these files (daemon,
mysql, www, nobody, etc.) so the easiest coarse of action is to make
modifiable only by root and viewable by all.