Rather than defaulting an an illegal value, the Fields plugin's settings
form now offers "First populated Date field" as the default option for
"Date field". Using this option will tell Date iCal to look through all the
fields in the View until it finds a populated Date field, and use that field.

So, if there are two Date fields specified in the view's FIELDS setting, and
at runtime the value of the first one is empty (e.g. because the node
doesn't use that field), then the second Date field's value will be used.

Renamed hook_date_ical_import_calendar_alter to hook_date_ical_import_vcalendar_alter, to match the export hook.

Also did some minor refactoring and comment editing.

Date iCal 3.0 is nearing completion! The only major task remaining
is to write the migration code.

This new version is still in a state of partial completeness. You may need to do
some manual fixing to get it working, due to a change I made in the classes
offered by this module. Try 'drush cc registry' if 'drush cc all' fails.

Please note that ALL of the hooks exposed by Date iCal have changed. They do
essentially the same things they used to do, but they're named differently.

The big change is that the Feeds plugin has been completely re-written to
conform to the Feeds APIs. It's now much more resilient and powerful. Feeds
Tamper will now work, and is in fact the prescribed way to alter data, since I
removed several alter hooks.

Some ical feed readers will erroneously take the DTSTAMP field into
consideration when comparing a new download to a previous one, and end up
treating all events as having been updated, because their DTSTAMP field is
different. This new option lets you get around those buggy readers.

I also added the CREATED field, which was embarassingly missing until now.

LAST-MODIFIED was only being included if $entity->changed was set, and there
may have been some cases where that wasn't true. Now, LAST-MODIFIED will be
included based on $entity->created, if $entity->changed isn't set.

According to the spec, EXDATE properties can have multiple values. However, many
popular calendar client don't support that, and only accept iCal feeds which
use multiple separate EXDATE properties. That is spec-compliant, though, so I
refactored Date iCal to do that for EXDATEs and RDATEs.

iCalcreator requires that you *not* call createTimezone($vcal, 'UTC'), because
the spec says to use zulu time rather than a UTC VTIMEZONE object.

Also fixed a copy-pasta bug that probably never manifested, since it would have
only had an effect on events that have an end date that's in a different
timezone from the start date.

date_repeat_split_rrule() calls functions from other .inc files, but doesn't
directly load those files. So I made Date iCal load them before calling it.

Added a version number to help me determine which version of Date iCal is being used by something who's having problems.

Added the hook_date_ical_post_render() alter hook.

date_ical_format_text() was going way overboard on it's attempts
to make text iCal compliant. I got rid of all the escaping, and also
all the extra endlines which the drupal function was adding at 80-char
boundries.

I added the summary_field option to option_definition, which should
fix several (surprisingly unreported) errors related to Features and first-time
setup.

Added the view object as a parameter for theme_date_ical_icon, which gives
additional context for any module that would like to override that theme.

Applied patch #11 from [#1922658] to get around iCalcreator limitation with stream wrappers. Also made the amount of whitespace on blank lines consistent throughout the project.

- Issue #1529506, Added optional webcal:// support.
- Issue #1890736, Added ability to exclude the X-WR-CALNAME property.
- Issue #1565410, Sites with "Clean URLs" disabled can now download feeds normally.
- Several minor bigfixes, and cleanup of the iCal icon theming.

If the user specified a date field in the Show settings which didn't exist in one or more of the entities which passed through the View, the rendering process would crash. This should no longer be the case.