[Guidelines change] Changes to the packaging guidelines

[Jason L Tibbitts III]

Here are the recent changes to the packaging guidelines.

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Many changes have been made to the Ruby packaging guidelines to reflect
the current state of Ruby packaging.

* https://fedoraproject.org/wiki/Packaging:Ruby
* https://pagure.io/packaging-committee/issue/710

Note that the macros required for some of those guidelines might still
be making their way into the stable releases.

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The Libraries and Applications section of the guidelines was modified to
favor independent packaging of applications and to discourage separate
graphical applications from having dependencies on each other.

* https://fedoraproject.org/wiki/Packaging:Guidelines#Libraries_and_Applicatio...
* https://pagure.io/packaging-committee/issue/694

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An exception allowing the use of a specific subdirectory in /etc/opt by
Chrome native messaging extensions was approved.

* https://fedoraproject.org/wiki/Packaging:Guidelines#Limited_usage_of_.2Fopt....
* https://pagure.io/packaging-committee/issue/767