Major test reorganization and rationalization

- t/lib/Test.pm renamed to t/lib/TestUtils.pm; all files now
  have "use lib 't/lib'" and load that as "use TestUtils"

- t/lib/TestUtils.pm no longer has tml running methods

- t/lib/TestMLTiny.pm has been streamlined to only deal with
  TestML issues; it relies on TestUtils for slurp

- t/tml-local now contains all .tml files that are like unit tests
  of YAML::Tiny behaviors

- t/tml-spec (renamed from t/testml) is where YAML spec tests should go

- t/tml-world contains all .tml files that are "real world" exampled

- all the files have been created/moved to t/3*

- More YAML.pm comparison moved to xt

- Lots of deduplication of cargo-cult test code

- Lots of moderniation of test files

- Depends on Test::More 0.99 for the latest bug fixes