replaced problemaic typedef to basic_format::string_type with plain basic_string

hopefully solve vc7 issue


[SVN r22141]

libs/format

@@ -1 +1 @@
-Subproject commit 18253a24d8d8afcd8bd183370bc3c294d2216d40
+Subproject commit d6bfa62c7aca6d0108363c7ed3c0afe356bb0b81