* Source/GSUnicode.c: Initial double formatting implementation. Only supports inf and nan for now.
* Tests/CFString/format_errors.m: Test for common errors.
* Tests/CFString/format_float.m: Test for inf and nan.

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/corebase/trunk@38112 72102866-910b-0410-8b05-ffd578937521