SimplePages maximum slug length is too long to display

[zerocrates]

Imported from Trac ticket #134 reported by kris on 2010-09-21:

Page slugs in SimplePages may be up to 255 characters in length. Anything approaching that is far too long to display correctly. For example, a page slug of 250 characters will run the rest of the content off the page on the SimplePages admin panel and may cause problems elsewhere.

Corollary to this is that having multiple nested pages with slugs approaching 255 characters may exceed the maximum recognized URL length of browsers like IE [http://www.boutell.com/newfaq/misc/urllength.html]