moved event details to the left if it is a single day event
added "Add new" and "Duplicate" button in edit event view
added information about event duplication in new event page
changed standard value for el_head_feed_link to true
removed obsolete code
only flush rewrite rules if required (after modifying the "el_enable_feed" option; added option to change feed name

issue #74
added option to change event list feed description
decode html entities in filterbar_items string
added filterbar items "daterange" (to view all, upcoming and past)

issue #69
fixed filteritem name in help text
added check if $post is available
updated screenshots
preparation for version 0.6.8
Merge branch 'develop'