Update for CotEditor 1.5.1
Fix menu item title
Revert "Change requirement for 1.5 on top page"

This reverts commit 320c24a134090775449d8eaef8493e04e1509c8d.
Merge commit '5a97beab5d4d60194221607783e820233920361c'
appcast for 1.5.1