Google hangouts: Bump to 5.4.2.0

Verified working with Firefox, however it hangs Chromium v37 (current dev) because of the LD_PRELOAD and while it doesn't hang Chrome v35 (current stable) I'm not sure that it works in there.

OTOH, Chromium 37 seems to have video calling without the plugin (just install the extension) so then it isn't needed any more.