Software Center crash: 'package-install' missing

[Avi Romanoff]

Here's the full output when running `software-center-gtk3` (or `software-center` from terminal on the March 30th 64bit livecd):

elementary@elementary:~$ software-center-gtk3
2014-04-04 20:38:24,559 - softwarecenter.ui.gtk3.app - INFO - setting up proxy 'None'
Traceback (most recent call last):
  File "/usr/bin/software-center-gtk3", line 130, in <module>
    app = SoftwareCenterAppGtk3(options, args)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 407, in __init__
    self.icons)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/panes/historypane.py", line 79, in __init__
    self._get_emblems(self.icons)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/panes/historypane.py", line 199, in _get_emblems
    pb = icons.load_icon(emblem, self.ICON_SIZE, 0)
gi._glib.GError: Icon 'package-install' not present in theme
elementary@elementary:~$