1. Fixed the shortcode issues and added some minor validations.
Merge remote-tracking branch 'origin/postmedia' into postmedia

Conflicts:
	lib/KalturaHelpers.php
1. Removed AllInOneVideoWidgetPlugin.php adn SidebarWidgetController.
2. Added more santitization for strings.
3. Removed SQL logic from WPModel
1. Changed _e function to esc_html function.
2. Added escaping to:
adminWarning(), mediaButtonsContextFilter(), commentFormAction(), shortcodeHandler(), savePost(), displayWidget(), videopostsStep3()
2. Added escaping to:
adminWarning(), mediaButtonsContextFilter(), commentFormAction(), shortcodeHandler(), savePost(), displayWidget(), videopostsStep3()

Some are weird excaping I can't really do.
2. Added sanitization for URL in Kaltura Sanitizer.
1. Changed version to 2.6 for WP VIP submission.