Window List broken on Vertical Panel in Mate

[Luke]

Steps to reproduce the problem:
1. Create a vertical panel in Mint Mate 17(mine is on the Left)
2. Add a Window List to it and experiment with the size settings
3. Set the width to 30-75 pixels
4. Open more than 7 windows

Result:
Windows List will rapidly flip between one column and two columns, spiking the CPU and making the panel unusable.

Cause:
Mate1.8 requires an updated libwnck

See:https://github.com/mate-desktop/mate-panel/issues/58

$ lsb_release -rcd ; uname -r
Description: Linux Mint 17 Qiana
3.13.0-24-generic

[Vlad Orlov (monsta)]

This is finally fixed in Mint 18.2 with migration of MATE to GTK+3.