Report bugs spotted by window-picker-applet audit upstream

Two C experts read the code and spotted a few bugs.

They should be solved by the attached patches which should now be tested and reported upstream.

Attachments

• 0001-Fix-about-dialog-logo-leak.patch
• 0002-Fix-configuration-options-not-properly-marked-as-tra.patch
• 0004-Avoid-GTK-namespace-pollution.patch
• 0005-Speed-up-some-private-data-access.patch
• 0006-Don-t-leak-task-title-text-attributes.patch
• 0007-Use-proper-event-time-when-closing-a-window-in-respo.patch
• 0003-Fix-improper-pixbuf-lifetime-handling.patch

Related issues

• Related to #7349 (closed)

Original created by @alant on 7365 (Redmine)