Add reason for skipping syntax tests

This might help debug issues like the failing Travis build in PR #7895.
added license to sync
Add Yate.app v3.2
Add MP3Gain Express v1.2
Merge pull request #7901 from vitorgalvao/fix-7899

Fix 7899
cookie.rb now uses :latest
macx-youtube-downloader.rb now uses :latest
Merge pull request #7900 from claui/syntax-test-add-hint

In syntax tests, amend `skip` directives to carry the reason for skipping
enable latest ``legacy`` version, Snow Leopard compatible

Closes #7868.
Merge pull request #7902 from vitorgalvao/fix-7868

enable latest ``legacy`` version, Snow Leopard compatible
enable Snow Leopard compatible version

Closes #7867.
Snow Leopard compatible poedit.rb
Merge pull request #7903 from vitorgalvao/fix-7867

enable Snow Leopard compatible version
enable latest ``legacy`` version, Snow Leopard compatible

Closes #7866.
Merge pull request #7904 from vitorgalvao/fix-7866

enable latest ``legacy`` version, Snow Leopard compatible
Snow Leopard compatible time-out.rb
move time-out app artifact back out of conditional
simplified updated of playlist-assist.rb
simplified updated of dupin.rb
moved appcast on scroll-reverser to else