Resolves #343 GUI and Frame Refactor

Major rewrite of the GUI into a module and view form, also using a new Feed class. The frame and frameset data structures have also been rewritten to support memory pooling and response frames.

components/operators/src/fusion/mvmls.cpp

@@ -47,8 +47,19 @@ bool MultiViewMLS::apply(ftl::rgbd::FrameSet &in, ftl::rgbd::FrameSet &out, cuda
 	bool show_consistency = config()->value("show_consistency", false);
 	bool show_adjustment = config()->value("show_adjustment", false);
 
-    if (in.frames.size() < 1) return false;
-    auto size = in.firstFrame().get<GpuMat>(Channel::Depth).size();
+    if (in.frames.size() < 1 || in.count == 0) return false;
+	cv::Size size(0,0);
+	for (auto &f : in.frames) {
+		if (f.hasChannel(Channel::Depth)) {
+			size = f.get<GpuMat>(Channel::Depth).size();
+			break;
+		}
+	}
+    
+	if (size.width == 0) {
+		in.firstFrame().message(ftl::data::Message::Warning_MISSING_CHANNEL, "Missing Depth Channel in MVMLS operator");
+		return false;
+	}
 
     // Make sure we have enough buffers
     while (normals_horiz_.size() < in.frames.size()) {