danielsh (the constant-time bit)

Suggested

r1175336

r1175336 | jcorvel | 2011-09-25 03:59:12 -0500 (Sun, 25 Sep 2011)

* publish/docs/release-notes/1.7.html
  (svnlook-filesize): Mention that it's a constant time operation, and
   elaborate a bit on the typical use-case.

Suggested by: danielsh (the constant-time bit)