* fix the duplicated 'exerpt' field in case of multiple events aggregation.
* update date calculation if the 'unit' attribute is provided within the important feed.
* update the category detection with the 'name' instead of the 'slug' because some languages have special chars that are url encoded.
* update the url encoding.
* improve the existing event detection in case of feed update.
* force country code transcription from 'xe' to 'gb' for england.
* leave HTML comments in the description of the ESS feed.
* set 'hour' as default value for every durations.
* update the ESS library that create the feeds.

git-svn-id: https://plugins.svn.wordpress.org/events-manager-ess/trunk@848743 b8457f37-d9ea-0310-8a92-e5e31aec5664