Effect's progress bars are displayed as runaway window

[grofaty]

Pinta master on Windows XP:
1. Open some large image e.g. http://www.pinta-project.com/Images/ss2-800.jpg
The idea is to have big image that effects takes many seconds to apply so progress bar is displayed.
2. Effects | Polar Inversion.
3. Amount = -1
Quality = 5
Edge Behavior = Wrap.
4. Click on OK button to make this effect applied.
5. Problem appears. Render Effect window is displayed outside of Pinta, so run-away window appears. See attachment for details. Expected: No run-away window.

This problem also appears using other effects (e.g. Ink Sketch, Oil Painting, many others), actually it looks like when ever there is few seconds delay (to much work to be done in second or so) this run-away progress bar appears.

P.S. Not the most important bug, so probably can be set as Low priority and post 1.5 release.

[Cameron White (cameronwhite91)]

Fixed: https://github.com/PintaProject/Pinta/commit/64b0b662544dc65d56d345009a1201620b0e046a