Switch windows build to full build

src/scripts/mkwinrelease.ps1

@@ -1,4 +1,4 @@
-if (-not (Test-Path env:QT_STATIC)) { echo "QT_STATIC is not set. Please set it to the directory with the static build of QT"; exit; }
+if (-not (Test-Path env:QT_DIR)) { echo "QT_DIR is not set. Please set it to the Qt directory from where you'd like to build. Usually, this is the installation directory of Qt."; exit; }
 if (-not (Test-Path env:APP_VERSION)) { echo "APP_VERSION is not set. Please set it to the version you want to build, like 0.1.6"; exit; }
 
 $target="zcash-qt-wallet-v$Env:APP_VERSION"
@@ -10,7 +10,7 @@ Remove-Item -Path release -Recurse | Out-Null
 
 # Run qmake
 echo "Configuring"
-& "$Env:QT_STATIC\bin\qmake.exe" zcash-qt-wallet.pro -spec win32-msvc "CONFIG+=release"
+& "$Env:QT_DIR\bin\qmake.exe" zcash-qt-wallet.pro -spec win32-msvc "CONFIG+=release"
 
 echo "Building"
 nmake *>$null
@@ -20,7 +20,7 @@ Move-Item release/zcash-qt-wallet.exe release/$target | Out-Null
 
 echo "Copying"
 # No need for deploy, since we're using a static Qt5 library
-& "$Env:QT_STATIC\bin\windeployqt.exe" release/$target/zcash-qt-wallet.exe *>$null
+& "$Env:QT_DIR\bin\windeployqt.exe" release/$target/zcash-qt-wallet.exe *>$null
 Copy-Item LICENSE release/$target | Out-Null
 Copy-Item README.md release/$target | Out-Null