Snow Leopard detection for painting background

[GoogleCodeExporter]

What steps will reproduce the problem?
1. You must have Snow Leopard
2. Create JFrame
3. Call MacUtils.makeWindowLeopardStyle(getRootPane()); // issue here
2. Add PreferencesTabBar or UnifiedToolBar.
3. Compile/Run
You will realize that the background is paint manually as if it was running in 
a non-Mac or non-Leopard os (which has different colors than Snow Leopard 
colors)

What is the expected output? What do you see instead?
The fix is to simply never paint the background manually. Instead, use the 
system property to set rootPane to Cocoa, and make the TabBar/ToolBar 
transparent. Also, there should be a check for OS >= 1.6 instead of just 
checking 1.5.

What version of the product are you using? On what operating system?
0.9.5

Please provide any additional information below.
I found previous version (cannot tell which one) that doesn't have this 
problem. I assume the reason was because it didn't try to draw the background 
at all back then.

Thanks.

Original issue reported on code.google.com by AREX...@gmail.com on 28 Mar 2011 at 4:27