0024284: Some trivial warnings produced by ICC 14

Eliminated ICC 14 warnings:
# 82: storage class is not first (e.g. "int static f()"
# 2621: attribute "dllexport" does not apply here (e.g. "Standard_EXPORT typedef int qqint;")
# 2415: variable "..." of static storage duration was declared but never referenced
# 111: statement is unreachable (usually "break" after "return" in cycles)

src/Image/Image_Diff.cxx

@@ -70,7 +70,7 @@ namespace
   }
 
   static const Standard_Size NEIGHBOR_PIXELS_NB = 8;
-  struct
+  static struct
   {
     Standard_Integer row_inc;
     Standard_Integer col_inc;
@@ -100,7 +100,7 @@ namespace
           && aCol < theData.SizeY();
     }
   }
-  static const NEIGHBOR_PIXELS[NEIGHBOR_PIXELS_NB] =
+  const NEIGHBOR_PIXELS[NEIGHBOR_PIXELS_NB] =
   {
     {-1, -1}, {-1,  0}, {-1,  1},
     { 0, -1},           { 0,  1},

src/Image/Image_PixMap.cxx

@@ -261,7 +261,6 @@ Quantity_Color Image_PixMap::PixelColor (const Standard_Integer theX,
                              Quantity_Parameter (Standard_Real (aPixel)),
                              Quantity_Parameter (Standard_Real (aPixel)),
                              Quantity_TOC_RGB);
-      break;
     }
     case ImgRGBAF:
     {