fix detection of zlib when configuring for Windows

This was synced with qtbase/src/3rdparty/zlib_dependency.pri
which uses correct library name on Windows and allows it to
be overriden via ZLIB_LIBS.

Change-Id: Iec86caf202a0da51f9bb5a5e3d0c62eaed4050b7
fix detection of ICU when configuring for Windows

When linking to the static ICU libraries, you need to link
to advapi32.lib. This is not required in qtbase because the
library is automatically added to QMAKE_LIBS_CORE, so we do
the same here.

Change-Id: I6d548790de4feae4b1d05ff27fb814e933f71839
enable QtWebKit on Windows with MSVC

Change-Id: Idced2887b4608bed4c086a4f8912251384eef5be
WTF: fix build on Windows for static ICU

The logic used was changed to be in sync with that used
for the configuration tests.

Change-Id: I8ba654c85487c19144431a94c2337caebac60447