added support for multiple node iterations

Optimizes various effects, particularly blurs.

app/node/generator/solid/solid.cpp

@@ -58,7 +58,7 @@ bool SolidGenerator::IsAccelerated() const
   return true;
 }
 
-QString SolidGenerator::CodeFragment() const
+QString SolidGenerator::AcceleratedCodeFragment() const
 {
   return ReadFileAsString(":/shaders/solid.frag");
 }

app/node/generator/solid/solid.h

@@ -42,7 +42,7 @@ public:
   virtual QString Description() const override;
 
   virtual bool IsAccelerated() const override;
-  virtual QString CodeFragment() const override;
+  virtual QString AcceleratedCodeFragment() const override;
 
   virtual void Retranslate() override;