[Tracker] Merge applet and main preferences dialogs

[Luca Ferretti <elle uca libero it>]

On December I closed some bug reports on bugzilla, mostly related to
0.6.x stuff, obsoleted in trunk.

I've also closed bugs 532050 and 523320, but maybe I was really strict.
Actually, both bugs complaints about the inability to restore the applet
icon visibility in a simple way and I've to admit that split daemon and
applet preferences in two separate dialogs is not a good idea: normal
users don't mind the logical distinction, everything is a "Tracker"
preference.

So, questions:
      * are you planning to merge them, maybe in a future release?
      * if not or in meantime, could you please take a look at bug
        564038 (fix "Preferences" vs "Indexer Preferences" in applet
        menu

Thanks, Luca.