Issues [#1931020] and [#1935820]: Allow custom fields for summary. Fix repeating events causing duplicates. Add @file to DateIcalFeedsParser.inc

DateIcalIcalcreatorComponent::component is no longer protected. This allows hook_feeds_after_parse() implementations to alter it.

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.

Date iCal now requires Views v3.5+.

- 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.

Includes patches from issues 1895396 and 1462646.
Updated the README and the CHANGELOG.

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.