Image.Layer support begin

Rev: src/modules/Image/layers.c:1.1

.gitattributes

@@ -201,6 +201,7 @@ testfont binary
 /src/modules/Image/illustration.pike foreign_ident
 /src/modules/Image/image.c foreign_ident
 /src/modules/Image/image.h foreign_ident
+/src/modules/Image/layers.c foreign_ident
 /src/modules/Image/matrix.c foreign_ident
 /src/modules/Image/mkwmml.pike foreign_ident
 /src/modules/Image/operator.c foreign_ident