debathena-firefox-extension doesn't deal with ubufox.js transition

[andersk]

andersk@ozok-the-destroyer:~$ debsums -as ubufox
debsums: missing file /etc/xul-ext/ubufox.js (from ubufox package)

We fail to undivert /etc/firefox-3.0/pref/ubufox.js after conditionally diverting it, of course, but that’s only half the story. From ubufox.postinst:

    if dpkg --compare-versions "$2" le "0.9~rc2-0ubuntu1"; then
        mv_conffile /etc/firefox-3.0/pref/ubufox.js /etc/xul-ext/ubufox.js
    fi

So we also need to add conditional versioned dependencies on ubufox. Fun.

[jdreed]

OK, we should probably actually deal with this after punting for over a year. I actually went and installed Jaunty and upgraded ubufox in an attempt to reproduce the broken state to see what's going on. After the upgrade to ubufox 0.9~rc2-0ubuntu1 or newer:

• /etc/firefox-3.0/pref/ contains ubufox.js.debathena and ubufox.js.debathena-orig
• /etc/xul-ext contains ubufox.js.dpkg-new
• /etc/xul-ext contains a broken symlink named ubufox.js pointing at the nonexistent target ubufox.js.debathena

Undiverting the file using c-p-d is going to trigger an ominous warning. We failed to divert /etc/xul-ext/ubufox.js (and we may not end up doing that), so my primary goal is to clean up the old diversion and restore some semblance of functionality to the user's machine. I think r25520 does that.