Use header bar for create web app dialog

https://bugzilla.gnome.org/show_bug.cgi?id=723803
Use header bar on history dialog

https://bugzilla.gnome.org/show_bug.cgi?id=723803
Use header bar on encodings dialog

https://bugzilla.gnome.org/show_bug.cgi?id=723803
Use header bar on preferences dialog

https://bugzilla.gnome.org/show_bug.cgi?id=723803
Make confirmation dialog modal

https://bugzilla.gnome.org/show_bug.cgi?id=723803
Use header bar on cookies dialog

https://bugzilla.gnome.org/show_bug.cgi?id=723803
Use header bar on passwords dialog

https://bugzilla.gnome.org/show_bug.cgi?id=723803
Use header bar in clear personal data dialog

https://bugzilla.gnome.org/show_bug.cgi?id=723803
Use header bar in certificate dialog

https://bugzilla.gnome.org/show_bug.cgi?id=723803
Always make message dialogs modal

https://bugzilla.gnome.org/show_bug.cgi?id=723803
Use header bar for bookmark properties dialog

https://bugzilla.gnome.org/show_bug.cgi?id=723803
Use header bar for add language dialog