Closing variables panel closes the manage libraries panel

Small bug to report.

1. Open both the Variables panel and the Manage Libraries panels.
2. Close the Variable panel using the X
3. The Manage Libraries panel closes

The opposite behavior is also strange:

1. Open both the Variables panel and the Manage Libraries panels.
2. Close the Manage Libraries panel using the X
3. Both panels close

Additionally, the ability to bring either panel to the front would also be a nice improvement.