change zoom action shortcuts more in line with Preview and avoid clash with zoom out standard alternative
change zoom action shortcuts more in line with Preview and avoid clash with zoom out standard alternative

git-svn-id: cb3fc60f0f557b927b8032d8a94e869b6f9f230b@7566 0fceea05-a30d-0410-8a8b-80ef821fb0a1

camillobruni/skim,camillobruni/skim,camillobruni/skim,camillobruni/skim