Make tunables/share play well with aliases
This reverts commit aa302220.
Space-separated list of values don't play well with aliases. For example, in Tails, despite this alias rule:
alias / -> /lib/live/mount/rootfs/*.squashfs/,
… the Tor Browser profile denies access to /lib/live/mount/rootfs/filesystem.squashfs/usr/share/mime/mime.cache, which should be equivalent to /usr/share/mime/mime.cache. That's fixed by using alternations instead; too bad they're less readable.
Candidate for master and 2.13.