basic_oalttrsingstream instead of outsstream, and 'parse-once' now means copying a static const format object (which can be thread safe) rather than using one format object all the times

[SVN r22108]

libs/format

@@ -1 +1 @@
-Subproject commit e767184292dec6add4d9b0991d2877f15fb3f864
+Subproject commit 97722222429964edd7f187cc49f4a3e3a5c7c472