winrtrunner: Accept backslashes as well when looking for manifest file

The mapping file might contain paths having slashes as well as
backslashes as separators. When looking for the manifest file in this
list the kind of separators used should not matter.

Change-Id: I80e36f3bc4d3f80c34291bfa845b345f5638f88d
Reviewed-by: Andrew Knight <andrew.knight@digia.com>
windeployqt: Disable d3dcompiler deployment on WinRT

This is no longer necessary for WinRT 8.1, because d3dcompiler_qt links
directly to the d3dcompiler.

Change-Id: Ic1d1261e9d16290ca7d4c2c5305d04092674333e
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Maurice Kalinowski <maurice.kalinowski@digia.com>