[ChangeLog][qmake] Introduced the variables
WINDOWS_TARGET_PLATFORM_VERSION and
WINDOWS_TARGET_PLATFORM_MIN_VERSION for overriding the default values
of WindowsTargetPlatformVersion and WindowsTargetPlatformMinVersion in
Visual Studio project files.
The code to determine the default values is moved to qmake feature
files. A common/windows-desktop.conf file is introduced for variables
common to all non-UWP Windows mkspecs.
The package_manifest feature uses WINDOWS_TARGET_PLATFORM_VERSION as
default value for WINRT_MANIFEST.minVersion, and
WINDOWS_TARGET_PLATFORM_MIN_VERSION for
WINRT_MANIFEST.maxVersionTested respectively.
Task-number: QTBUG-53654
Change-Id: I251ec7f9b804c9bc9f7d571f5b43d52b2a2d99d3
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@qt.io>
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>
