SOC-4239: [IE8]No user avatar in activity's comment.

Problem analysis:
- IE8 browser needs explicit position definition while other browsers don't require.

Fix description:
- Define the position of avatar in activity's comment.
SOC-4222: [User Popup] Incorrect Activity link when Platform runs inside an IFrame

Problem analysis
- The target window is currently wrong.

Fix description:
- Set the target to current window.