Add DSLogic capture, signal conversion and DSView decoders

tools/dsview/tests/gate_summary_test.cpp

@@ -0,0 +1,24 @@
+#include "gate_summary.h"
+#include <cassert>
+int main() {
+    GateSummary summary;
+    assert(summary.severity(true) == 1); // Empty captures are not OK.
+    summary.observe(0); summary.observe(1); summary.observe(2);
+    assert(summary.severity(false) == 1);
+    assert(summary.severity(true) == 0);
+    summary.observe(0); // A command without a complete ACK at EOF.
+    assert(summary.severity(true) == 1);
+    summary.observe(2);
+    assert(summary.severity(true) == 0);
+    summary.observe(3);
+    assert(summary.severity(true) == 1);
+    summary.observe(4);
+    assert(summary.severity(false) == 2);
+    assert(summary.severity(true) == 2);
+    summary.observe(2); // Later good events never hide earlier faults.
+    assert(summary.severity(true) == 2);
+    summary.reset();
+    assert(summary.severity(true) == 1);
+    summary.observe(5);
+    assert(summary.severity(true) == 2);
+}