[Epiphany] Bookmarks tasks

[Marco Pesenti Gritti <mpeseng tin it>]

I wrote a prioritized list of tasks for the bookmarks system. I
committed it in cvs as doc/bookmarks.txt. It's not something that funny
to read but if you are interested to the problem you may want to take a
look. If I'm missing something, let me know.
Note that we dont necessarily need to implement all of them, some could
be just dropped as unimportant.
I have an idea about the changes we need to current interface to fit
that list better. I plan to come with some screenshots later.

Marco