Inform users about the use of spyware/spam links in older versions of the Kaltura module

As discussed in #847952: Suspend CVS account for Kaltura (spyware) the Kaltura module has a spotty history of spam SEO links, and undisclosed data collection.

These issues are being sorted out in #847952: Suspend CVS account for Kaltura (spyware). Until that issue is satisfactorily resolved, I suggest that the top of the project page contain the following text:

"Older versions of the Kaltura module contained hidden SEO links and an undisclosed iframe that collected site information during the install process. For a full review of these concerns, see this issue."

Once #847952: Suspend CVS account for Kaltura (spyware) gets resolved, this text can be removed from the project page.

I'm putting this here for community feedback. While I have the rights to just edit the page and add this in myself, I did not want to short circuit the ability of the community to provide feedback.