Don't try to set the wrong value for cookie policy

The builder template system wants us to to use underscores for
the widget names but the gsettings values for these widgets
use dashes. So, translate between then in the mapping functions.
prefs dialog: set dialog type hint
Create a new clear data dialog

https://bugzilla.gnome.org/show_bug.cgi?id=720113
Create a new cookies dialog

https://bugzilla.gnome.org/show_bug.cgi?id=720113
Hook up new cookies dialog to prefs dialog

https://bugzilla.gnome.org/show_bug.cgi?id=720113
Remove personal data manager

https://bugzilla.gnome.org/show_bug.cgi?id=720113
Updated POTFILES.in
Mark more some strings as translatable
Updated Hebrew translation