PHPDoc @link comment
PHPDoc of the cron class
removed duplicated LICENCE file
moved cron in admin side of plugin initialization
clear WordPress schedule hook on plugin desactivation
removed useless comments
add call of wp_next_scheduled()

Check existence of schedule by calling wp_next_scheduled() function
instead of looping in _get_cron_array()
Merge branch 'scheduling' of https://github.com/Spoon4/slideshare-posts-import into scheduling

Conflicts:
	public/class-slideshare-posts-import.php
	slideshare-posts-import.php