This update for xfce4-cpugraph-plugin fixes the following issues:

Update to version 1.2.8

* Update authors
* Add option to enable / disable SMT statistics (disabled by default)
* Migrate to Xfconf
* Move settings functions into namespace
* Require Xfconf library
* Add 24px icon, cleanup SVG metadata
* Update copyright year
* Display detailed CPU load on Linux
* Improve tooltip
* build: Add GLib requirement
* Translation Updates