Technically we could deprecated exo_url_show() and use gtk_show_uri(), but since the gtk version uses GIO in the background, the preferred applications frameworkin exo is not used. The solution would be a GIO module for http uris. See also bug #5671.
Working on this. I have the GIO module ready (extension based on GDesktopAppInfoLookup). The following changes have been made so far: * GIO modules to launcher the exo-helper for various 'known' URIs (also fixes the bugs #4227 and #4497). * Changes to exo-open to send a valid URI to gtk_show_uri, in case no --launch type is defined. * Dropped the exo-uri.{c,h} files. People can use gtk_show_uri(). The about dialog hook has been moved to exo-gtk-extensions and renamed to exo_gtk_url_about_dialog_hook. It is still needed because Gtk uses gtk_show_uri by default since version 2.18. This also requires the addition of a FileManager launcher in exo (bug #4445). Once that is pushed (will create a new branch until everything is tested) I'll take a look at the other bugs related to this topic too.
Pushed in branch.