Fix date_limit_format() to be sure the 'T' is stripped out of ISO dates with only date or only time.

#456460 Break out simple themes for date_display_single and date_display_double for easier control by themers of separator and other html.

#452420 Revert change of hyphen to dash in date display, dash is handled badly by token and elsewhere, patch by thinguy.

#347080 Using 'first' and 'last' is more reliable than '+1 week' in strtotime(), patch partly by jonathan_hunt.

#417032 Fix typo that caused date fields using text widget not to have values saved, patch by tatere@drupal.org.

#418206 All date elements should be in datetime format when processing elements, patch by scottgifford, vince, and karens.

#414290 Update timezone form_alter to account for difference between Event version 1 and 2, patch by ron_s.