Revert "Revert "Merge branch '1.3.x' into CNMSUP-43", since version 1.3.6 introduces a new dependency that makes TinyMCE not longer works with Plone before 4.3"

This reverts commit bcb5395c78d845e43fde35f3e887335de9299624.
Revert "Revert "This was already fixed in version 1.3.6 from commit 1f685d0f7956edfa2b4071259ce00d80923b7d28, so using that instead""

This reverts commit 6353cd193f6066eaeda48898a45deff3f3c23d44.
Merge this branch back to what 1.3.x had but revert the plone.app.layout pinning so it works with Plone 4.2 again