HiDPI OS-specific issues / next steps

[Keith Curtis]

Hi;

I've got another patchset I've submitted to Gerrit. Assuming that goes
okay, the next steps are:

* test / figure out what the most important issues are
* whether / how to enable it for the Mac (Currently LibreOffice runs
in compatibility mode where things are auto-doubled.)
* testing on various Windows versions
* what to do for KDE, Xfce, Unity, etc.

I only have Gnome / KDE / Xfce installed so I can only work on those scenarios.

Advice / help appreciated. It seems it could take a minor release to
work through some of these details.

-Keith