Fixed Generic tag editor - GRADIENT filters fields

Disallow manually adding items to convolution matrix

libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/types/annotations/SWFType.java

@@ -48,4 +48,6 @@ public @interface SWFType {
 
     //Count to add to countField
     int countAdd() default 0;
+    
+    boolean canAdd() default true;
 }

libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/types/filters/CONVOLUTIONFILTER.java

@@ -62,7 +62,7 @@ public class CONVOLUTIONFILTER extends FILTER {
     /**
      * Matrix values
      */
-    @SWFType(BasicType.FLOAT)
+    @SWFType(value = BasicType.FLOAT, countField = "matrixX * matrixY", canAdd = false)   
     public float[] matrix = new float[] {
         0, 0, 0,
         0, 1, 0,