Update gedit3 to 3.16.2

Highlights from the release notes:

- Fix gedit --wait when listing multiple files
- Improve error reporting when failing to load private lib
- Performance improvements for groups of text insertions/deletions
- Do not merge xml translation in gschema files
- Rework some of the printing code
- Improved documentation
- Improved open document selector
- Start to rework the replace dialog
- Use the new color scheme chooser
- External tools plugin: fix document saving
- Various bug fixes
- Many new and updated translations

For full details see:

https://git.gnome.org/browse/gedit/tree/NEWS?id=3.16.2

(prlw1)