Update the changes log with all the changes up to this point.
Overhaul isa_ok() and fix it for perl 5.17.

5.17 (and thus 5.18) changes how '#!%@#$!blah'->isa is resolved.  Now
any string will be treated as a class name.  See rt.perl.org #105922

This required changes to the isa_ok() and I decided to overhaul
the logic so it's more organized.  I also changed the formatting,
hopefully more sensibly.

For #353
Update the change log.
Require Scalar::Util used by isa_ok()

1.13 is the version which shipped with 5.8.1.

Don't make 5.8.1 the minimum Perl to allow it to still work on 5.6
if they have Scalar::Util.
Version 0.98_04
Add a shorter work around for the UTF-8 output problem to the docs.

Downside is that 'use open' can be a bit flakey in older Perls.
Not sure how to document that.
Change subtest to auto-note at the beginning of the test

Fix t/subtest/*.t to work with new auto-note
Fix outergroup test in t/subtest/predicate.t
Fix Test::Builder::Tester::complaint to not output double-spaced $wanted
Indent the subtest note with the subtest.

Discussed in #290.
Log the subtest note change.
Fix Test::Builder::Tester so it works with subtests.

They already work in TB1.5 and this wasn't hard to fix.

For #350
Merge pull request #364 from schwern/subtest_note_at_start

Subtest note at start
Merge pull request #365 from schwern/tbt_subtest

Fix Test::Builder::Tester so it works with subtests.