Release v0.20130717 (and others)

Baked a new release v0.20130717:
  * [DEPENDENCY] Upgraded to rails 3.2.13.
  * Fixed #30: Relax markdown emphasis parsing to avoid adding emphasis to words_containing_underscores.
  * Fixed #22 and #33: avoid double-output of cache block for filtered events.
  * Fixed #35: Use 'medium' git log format for footer version number.
  * Fixed #36, #37: Limit the number of links in event descriptions to three.
  * Fixed Google Code issue #280: Strip whitespace from venue fields.
  * Fixed #38: Fixed display of events with no end time
  * Added Schema.org support to event markup.
  * Updated spam blacklist.

Also, manufactured tags and wrote release notes for past stable releases
that were never officially tagged or released.