Check for non valid keys and fallback to last used one

[Claudio Moretti]

Binary package hint: firefox-3.5

As said, when removed, it does not clean all its "registry" entries (is this correct? to me sounds a lot Micro$oft-ian), and when I try to open, for example, an FTP server from "Places -> Connect to server", I get an error that sounds like "Child process /usr/bin/firefox-3.5 execution failed. No such program." (translated on-the-fly from Italian).
I have cleaned this by manually deleting, in "gconf-editor -> desktop -> gnome -> url-handlers" the "command" key for "ftp" (i didn't know how to replace it; "nautilus", maybe?).
Also, I found out that at least another entry (I can't remember which one) has not been modified

[Pedro Villavicencio (pedro)]

I've talked to Alexander about this:

"<pedro_> asac, is this a problem with the ubuntu package? bug 375637
<ubot4> Launchpad bug 375637 in firefox-3.5 "Uninstalling Firefox 3.5 does not remove all gconf entries" [Undecided,New] https://launchpad.net/bugs/375637
<asac> pedro_: thats a good question. i am not sure
<asac> those are user configs
<asac> feels like only thing that could do better is gnome-settings-daemon ... or something
 maybe would need to check on each run if certain keys are still valid
 and if like the command line handlers are not, fallback to the last used option that is still available
"

I'm reassigning this to gnome-settings-daemon for now, shall we send this upstream? Seb what do you think about the report?