Cleanup Analytics Module

Update the automatic link tracking for the analytics module to match what the UNLcms currently provides.

This will allow developers to control when/which links are automatically tracked using the `WDN.setPluginParam` method. Examples:
To change the file extensions tracked - `WDN.setPluginParam('analytics', 'extensions', 'pdf|zip');`
To disable file download tracking - `WDN.setPluginParam('analytics', 'tarckDownload', false);`
To disable mailto link tracking - `WDN.setPluginParam('analytics', 'trackMailto', false);`
To disable outbound link tracking - `WDN.setPluginParam('analytics', 'trackOutbound', false);`

Also disable the scroll depth plugin by default, allowing developers to manually enable it on pages they'd like those events to be tracked. (start discussion here)