Pop Up menu button (the one at the bottom of the folders list): changed
bezel style from deprecated NSSmallIconButtonBezelStyle to
NSRegularSquareBezelStyle.
menuRepresentation for pop-up menu is deprecated. Comment
out offending line.
Import.m: loadNibNamed:owner is deprecated in 10,8, but the replacement
is only available in 10.8 and later, so leave as is for the
moment.