Fixes annotate spacing (issue 7313082)

[dak]

https://codereview.appspot.com/7313082/diff/1/scm/skyline.scm
File scm/skyline.scm (right):

https://codereview.appspot.com/7313082/diff/1/scm/skyline.scm#newcode23
scm/skyline.scm:23: (define-public (skyline-pair::useable? skyp)
So why is this not non-empty-skyline-pair? or
skyline-pair-and-non-empty?  It is nice that you add a comment
explaining an incomprehensible term in about the same space that the
incomprehensible term takes, but why?  "useable?" is merely an
obfuscation of "non-empty?" and does not imply a check for being a
skyline pair at all any more than "non-empty?" does.  So why obfuscate
the name in the first place?  We don't get prices for new word
creations.

https://codereview.appspot.com/7313082/