Adding a GtkhtmlEditor::uri-requested repeater signal was a mistake.
It unnecessarily complicates URI handling and so the composer no longer
uses it -- instead it connects to GtkHTML::url-requested directly.
This also requires commit 203ce61e6ea19323914b9c459b2e79bde5db15be from
GtkHTML to work right. That commit changes GtkHTML::url-requested to a
G_SIGNAL_RUN_LAST so the composer's signal handler runs first. If the
composer can handle the URI request, it stops the signal emission so
that nothing else tries to use the freed GtkHTMLStream.
Henceforth consider GtkhtmlEditor::uri-requested to be deprecated.
7636c47051