added: ErrorCode::err_still_calculating (it's used when there is more than one thread)

git-svn-id: svn://ttmath.org/publicrep/ttmath/trunk@15 e52654a7-88a9-db11-a3e9-0013d4bc506e

TODO

@@ -1,5 +1,6 @@
 TODO TTMath Library
 ===================
 
-* add the method Mod (a remainder from a division) for the Big type
-
+* to add the method Mod (a remainder from a division) for the Big type
+* to add operators (or functions) and, or, xor
+* to add functions for generating random values

ttmath/ttmathtypes.h

@@ -217,7 +217,8 @@ namespace ttmath
 		err_functions_loop,
 		err_must_be_only_one_value,
 		err_object_exists,
-		err_unknown_object
+		err_unknown_object,
+		err_still_calculating
 	};