This reverts commit e4819a1b, reversing
changes made to b6ec41ca.

Now that we're ready to test again, need to revert the revert to put the filtering UI back in.

This reverts commit 66889b87, reversing
changes made to 0dd9c24e.

This was merged too early--it's still missing the filtering and display-your-cohort changes.
Will need to revert this revert later.

minor tweaks to dropdown text and addition of dropdown menu (without data links) for intructor visilibility dropdown in main discussion forum;