Toob Flanger, Stereo Reverb, bug fixes

- support state in factory presets.
- Use uncompressed json for settings files.
- Set current plugin preset name to last loaded plugin preset.
- Append plugins after  start node,  before end node fixed.
- Correctly release web socket when web app goes idle.
- Fit and finish issues.

src/Uri.hpp

@@ -70,6 +70,10 @@ public:
     {
         set(text);
     }
+    uri(const std::string&text)
+    {
+        set(text.c_str());
+    }
     void set(const char*text);
     void set(const char*start, const char*end);
 private: