Add explicit character encoding specifications in 39 more RGL modules

To silence warnings and avoid potential problems after changing the default
encoding to UTF-8.

lib/src/russian/SymbolRus.gf

@@ -1,7 +1,7 @@
 --# -path=.:../abstract:../common
 
 concrete SymbolRus of Symbol = CatRus ** open Prelude, ResRus in {
-
+flags coding=utf8;
 {- TODO! -}
 lin
   SymbPN i = {s = table  {_ => i.s} ; g = Neut; anim = Inanimate } ;