Language selector improvements for the Karmic cycle

Work items:
language-pack split in langpack-o-matic for Chinese: DONE
add code to gnome-language-selector to handle the splitted langpacks: DONE
UI change in glade: DONE
code change for fallback language settings: POSTPONED
code change for environment variable settings: POSTPONED
code change for IME setting: DONE
remove language-support-extra and language-support-translation from langpack-o-matic: DONE
remove language-support-extra from gnome-language-selector: DONE
modify packages with separate translation packages to place a trigger in update-notifier:
add code to gnome-language-selector to scan for missing translation packages: DONE
write release notes and test plan:

pitti, 2009-06-18:
 - Please remove BoF notes from whiteboard (if there is something important left, please integrate into spec)
 - Does it really make sense to offer a tab "measurement"? This is all defined in the locales already; if we offer this setting, why don't we also offer paper format, start of week, currency, and everything else which is defined in locales? IMHO the main use case here is to set $LC_MESSAGES differently from $LANG, so perhaps as a first step the UI should just offer this? This is structurally much easier, otherwise you'd have to generate locales on the fly.
 - Did you make sure that ~/.profile is read by GNOME and KDE startup? (not just in a Terminal window when bash gets run)
 - "the most likely locale" is blurry; see above, I think we should avoid heuristics altogether here and just expose LANG (everything but translations) and LC_MESSAGES
 - summary talks about being able to select input method, but dialog just has a checkbox for this. This is fine when just one is available, but if we have e.g. scim and i-bus installed, it might make sense to show a combobox.
 - yay for dropping language-support-translations! :-)

pitti, 2009-08-07: Looks great now, thanks for the cleanup! Approved.

arnegoetje, 2009-09-10: need to postpone the fallback language setting and the environment variable setting, since it's UI freeze today. Unfortunately due to me having been sick the past three days and the rest of my family the weeks before that I didn't have the time I needed to code this. However, if time provides it and I don't get dragged into the translations swamp again, I will continue hacking on this, so that we can have the features in early karmic+1 cycle.