Fix image uploader for 1.9.3 and patch SUPEE-8788

[tgerulaitis]

This fixes the image uploader for Magento v1.9.3 and any other versions with SUPEE-8788 security patch applied. However, this also breaks compatibility with any versions that do not have the patch applied, so do with this as you wish!

[cproach]

This fixes uploading images for when they have been inserted into a cms page directly but I am unable to get the Browse button to work when navigating to CMS > Widgets and creating/modifying a widget here. Is this portion working for you or are you having the same issue here? I'm currently troubleshooting.

[cproach]

I found the fix. They modified head elements. The below needs to be added.

<action method="setCanLoadExtJs"><flag>1</flag></action>
<action method="addJs"><script>mage/adminhtml/variables.js</script></action>
<action method="addJs"><script>mage/adminhtml/wysiwyg/widget.js</script></action>
<action method="addJs"><name>lib/uploader/flow.min.js</name></action>
<action method="addJs"><name>lib/uploader/fusty-flow.js</name></action>
<action method="addJs"><name>lib/uploader/fusty-flow-factory.js</name></action>
<action method="addJs"><name>mage/adminhtml/uploader/instance.js</name></action>
<action method="addJs"><script>mage/adminhtml/browser.js</script></action>
<action method="addJs"><script>prototype/window.js</script></action>
<action method="addItem"><type>js_css</type><name>prototype/windows/themes/default.css</name></action>
<action method="addCss"><name>lib/prototype/windows/themes/magento.css</name></action>