Codechange: replace magic numbers and C-style arrays with C++-style array for share owners

src/company_type.h

@@ -40,6 +40,7 @@ static const uint MAX_LENGTH_PRESIDENT_NAME_CHARS = 32; ///< The maximum length
 static const uint MAX_LENGTH_COMPANY_NAME_CHARS   = 32; ///< The maximum length of a company name in characters including '\0'
 
 static const uint MAX_HISTORY_QUARTERS            = 24; ///< The maximum number of quarters kept as performance's history
+static const uint MAX_COMPANY_SHARE_OWNERS        =  4; ///< The maximum number of shares of a company that can be owned by another company.
 
 /** Define basic enum properties */
 template <> struct EnumPropsT<Owner> : MakeEnumPropsT<Owner, byte, OWNER_BEGIN, OWNER_END, INVALID_OWNER> {};