Log Message:
update to 0.72

changes:
- anydbm sorting with None values (sf bug 952853)
- roundup-server -g option not recognised (sf bug 952310)
- HTML templating isset() inverted (sf bug 951779)
- otks manager missing (sf bug 952931)
- mention DEFAULT_TIMEZONE requirement in upgrading doc (sf bug 952932)
- fix DateHTMLProperty so local() can override user timezone (sf bug
  953678)
- fix anydbm sort/group direction handling, and make RDBMS sort/group use
  Link'ed "order" properties (sf bug 953148)
- fix Interval editing (sf bug 954891)