Prevent 'char' from being used as numeric type

lib/luwra/types.hpp

@@ -194,8 +194,6 @@ LUWRA_DEF_NUMERIC(Number, double)
 LUWRA_DEF_NUMERIC(Number, long double)
 
 // Integral types
-LUWRA_DEF_NUMERIC(Integer, signed   char)
-LUWRA_DEF_NUMERIC(Integer, unsigned char)
 LUWRA_DEF_NUMERIC(Integer, signed   short)
 LUWRA_DEF_NUMERIC(Integer, unsigned short)
 LUWRA_DEF_NUMERIC(Integer, signed   int)