Merge lp://staging/~mvo/software-center/lp987321 into lp://staging/software-center/5.2

Hi Michael!

I'll approve this branch, because it is obviously correct and desirable.

I'm not sure however whether it is sufficient to solve the issue from the bug. The following things confuse me slightly:
- looking at http://paste.ubuntu.com/942544/ it would seem to give the impression that humanity-icon-theme is installed; on startup we append the humanity icontheme to the icontheme which is currently in use, so it should be able to find the icons?
- gnome-icon-theme depends on the hicolor-icon-theme which includes the desired icons, so it should be able to find the icons?
I haven't managed to reproduce the issue myself yet, but perhaps you have a better idea as to what's going on?

(Please do merge the branch as is, as it's a desirable change. Thanks!)

hicolor-icon-theme does not itself have them, its synpatic that has them and puts them into the hicolor namespace (which is probably a mistake) and that is confusing.

ah, cool, thanks for the clarification!