#224750 - com.sun.jdi.ClassNotLoadedException: Class java.lang.Class not loaded

Bug: http://netbeans.org/bugzilla/show_bug.cgi?id=224750

Description: In order to upload agent classes for Visual Debugger, we 
need to use some class loader. Originally, 
ClassLoader.getSystemClassLoader() was used, but this did not work for 
applications, which change their system class loader. This is why we 
tried to find out the JVM boot class loader via iterating through class 
loader parents.
The problem here is, that the top most root of the class loaders is not 
able to load some JVM classes, for some reason. This is why this fix 
chooses the second top one, the AppClassLoader.

Impact assessment: events logging feature of Visual Debugger is unusable.

Risk assessment: most of the Visual Debugger functionality depends on 
it's agent classes.

The fix was successfully tested by Jiri Kovalsky and reviewed by 
Jaroslav Havlin.

Fix: http://hg.netbeans.org/main-golden/rev/47c8af772632

Thanks for the review,
Martin.