double squish animation glitch when starting a program

[Ryan Thompson]

This is a bit difficult to describe, but easy to replicate.

To reproduce:
Set "Icon Effects" to "Squish"
Hover the mouse over a launcher icon, so that the squish & bounce animation is playing. It alternates between squishing down and bouncing up, as normal.
Click the launcher to launch the program (the program should not already be running, i.e. you should actually be *launching* it)
The icon squishes twice in a row, without bouncing. This is because the "hover" animation ends with a bounce, and the "launch" animation starts with one, so you get two in a row.

Short term solution: Remove the initial squish of the animation, or do nothing and deal with it.
Long term solution: On transitions from one animation to another, if the two animations are the same one, add code to skip the intro (i.e. the first squish) part of the new animation.