Disallow the use of config-specific source files with
the Visual Studio and Xcode generators. They don't have
any way to represent the condition currently.
Use the same common-config API in cmQtAutoGenerators. While
it accepts config-specific files, it doesn't have to support
multiple configurations yet.
Loop over the configs in cmTargetTraceDependencies
and cmGlobalGenerator::WriteSummary and consume all source
files.
Loop over the configs in cmComputeTargetDepends and compute the
object library dependencies for each config.
Don't try to show the windows, which would require a gui capable test
machine, and that's not guaranteed.
Automatically link to qtmain.a on Windows to avoid a policy warning. Set
policy CMP0020 to NEW by increasing the required version.
Don't attempt to run the test when using Windows.