include branch spec in delete confirmation message

Provide the user with slightly more confirmation that they're deleting
the branch they intended. This is useful particularly when cleaning up
stale branches via the Branch Manager.
Add '--date-order' option switch for 'magit-log'
remove dependency to epa

not worth breaking compatibility with emacs < 23 for just a face
Merge commit '5ea87cf'
Merge commit 'daf118f'
Merge branch 'master' into next