Pose modification operator

A few fixes for allowing runtime addition of network connections, but mainly the addition of a poser operator which maintains a pose database and allows framesets to be mapped and locked to any given pose.

applications/gui/src/frameset_mgr.cpp

+#include "frameset_mgr.hpp"
+#include <ftl/uri.hpp>
+
+static int frameset_counter = 0;
+
+int ftl::gui::mapToFrameset(const std::string &uri) {
+    ftl::URI u(uri);
+    return frameset_counter++;
+}