qga: Workaround for console redirection from non-interactive qemu-ga service

mingw-glib uses helper process to assist gspawn() api. There are two
versions of helpers, one with main() and another with WinMain() startup
routines.

Whenever gspawn() detects consoleless environment (and qemu-ga is running
in such environment as Win32 service), it chooses helper with main()
instead of WinMain. It is done by name, e.g.
gspawn-win32-helper-console.exe vs gspawn-win32-helper.exe

Running console-aware application like any win32 console apps from main()
crt initalized process results in redirection of stdout to console created
in crt startup instead of parent-provided handle connected to subprocess
pipe. Thus, stdout/stderr redirection do not work correctly.

The patch makes WinMain()'s version of helper be used as the only helper
shipped with qemu-ga package. Using only win32 helper ensures console
is created before any redirection and fixes stdout/stderr redirection
issue.

Signed-off-by: Yuri Pudgorodskiy <yur@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

qga/installer/qemu-ga.wxs

@@ -96,7 +96,7 @@
             <File Id="gspawn-win32-helper-console.exe" Name="gspawn-win32-helper-console.exe" Source="$(var.Mingw_bin)/gspawn-win32-helper-console.exe" KeyPath="yes" DiskId="1"/>
           </Component>
           <Component Id="gspawn-helper" Guid="{CD67A5A3-2DB1-4DA1-A67A-8D71E797B466}">
-            <File Id="gspawn-win32-helper.exe" Name="gspawn-win32-helper.exe" Source="$(var.Mingw_bin)/gspawn-win32-helper.exe" KeyPath="yes" DiskId="1"/>
+            <File Id="gspawn-win32-helper.exe" Name="gspawn-win32-helper.exe" Source="$(var.Mingw_bin)/gspawn-win32-helper-console.exe" KeyPath="yes" DiskId="1"/>
           </Component>
           <?endif?>
           <?if $(var.Arch) = "64"?>
@@ -104,7 +104,7 @@
             <File Id="gspawn-win64-helper-console.exe" Name="gspawn-win64-helper-console.exe" Source="$(var.Mingw_bin)/gspawn-win64-helper-console.exe" KeyPath="yes" DiskId="1"/>
           </Component>
           <Component Id="gspawn-helper" Guid="{D201AD22-1846-4E4F-B6E1-C7A908ED2457}">
-            <File Id="gspawn-win64-helper.exe" Name="gspawn-win64-helper.exe" Source="$(var.Mingw_bin)/gspawn-win64-helper.exe" KeyPath="yes" DiskId="1"/>
+            <File Id="gspawn-win64-helper.exe" Name="gspawn-win64-helper.exe" Source="$(var.Mingw_bin)/gspawn-win64-helper-console.exe" KeyPath="yes" DiskId="1"/>
           </Component>
           <?endif?>
           <Component Id="iconv" Guid="{35EE3558-D34B-4F0A-B8BD-430FF0775246}">