split format_test2.cpp : 2 tests dont apply to gcc-2.95 (showbase isnt even defined..)

so moved them into format_test3.cpp


[SVN r19971]

libs/format

@@ -1 +1 @@
-Subproject commit 5f62244997cc45a6f4aaeff3e0375233d9220184
+Subproject commit 7618d770c418fa520ee19404b57d8bcdb6c3628b