Bug 16937: homepage pref has been translated in the Korean bundle

To keep the browser.startup.homepage pref value out of translators
hands, all of the localized browser.properties files have been
removed and the pref value (about:tor) has been moved to a new
non-localized.properties file.

We no longer provide a value for spellchecker.dictionary, which
means non en-US users will probably need to set their spellchecking
language from the browser context menu or via about:config after
they install a dictionary for their language. The browser will also
consult the LANG environment variable and use a "default default"
of en-US if an en-US dictionary is installed.