This commit mostly:
* removes some (very) old messages or hacks (like those for ubuntu 10.4...).
* Moves lib-specific dependencies installations to upper level
(simpler to manage, and those are small enough packages).
* Uses new dnf package manager for fedora (sigh, we now have tree different commands for fed/suse/rehl).
* fixes or enhances some options for commandline tools.
* Force anew building of oiio package, due to insane dependencies of this one in recent distro.
Part of D1933.
3ccc61c03a