Windows packaging fixes to use new stack.pkg.yaml.

appveyor.yml

@@ -2,7 +2,7 @@ clone_folder: "c:\\stack"
 environment:
   global:
     STACK_ROOT: "c:\\sr"
-    STACK_YAML: "c:\\stack\\windows\\stack.yaml"
+    STACK_YAML: "c:\\stack\\stack.pkg.yaml"
     WIXBIN: "c:\\Program Files (x86)\\WiX Toolset v3.10\\bin"
 
 cache:

windows/make-windows-installer.bat

@@ -1,5 +1,5 @@
 @echo off
-stack install --test --stack-yaml ..\stack.pkg.yml
+stack install --test --stack-yaml=..\stack.pkg.yml
 if %errorlevel% neq 0 exit /b %errorlevel%
 for /f "delims=" %%a in ('stack path --local-bin-path') do @set BINPATH=%%a
 %BINPATH%\pandoc.exe -s --toc ..\MANUAL.txt -o MANUAL.html