Outline staus text of tooltip
Color of status of tooltip is arbitrary.
Because color of status is arbitrary, not all colors of all statuses of Gajim fit well with a color scheme every theme.
Outline text of status so that it would be better readable with most, if not with all themes.
\<p style="color: yellow">Away\</p> vs. \<p style="color: grey">Offline\</p> (I do not know how to outline HTML fonts without using CSS)