[Epiphany] Favicons and crashes on exit

[Marco Pesenti Gritti <mpgritti oltrelinux com>]

I reimplemented favicons in a better way to avoid all the crashes on
exit they was causing.
If you get problems with the new implementation please report them.

In theory the upgrade should work without problems, but if you get
crashes try to remove ...favicon...xml in ~/.gnome2/epiphany. Sorry for
the mess, I hope this is the last format change :)

I plan to release 0.4.2 soon and then shortly 0.5, but I would like to
be sure bookmarks/history/favicons works correctly. (mainly, they dont
get lost or corrupted). They use xml and changing formats later would be
a pain.

Marco