prune vestiges of DEPLOYMENT_PLUGIN

the code was broken since 5.0, as it still hardcoded the version number
4 for the plugin basenames.
wince is not supported any more, so there is no point in trying to
restore the code to function.

at a later point, we'll make QTPLUGIN universal enough to cover both
static and dynamic deployment.

Change-Id: I0911ce4aff7a799dd471d6218e046f13dca6d49e
Reviewed-by: Jake Petroules <jake.petroules@qt.io>
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>
Reviewed-by: Andy Shaw <andy.shaw@qt.io>

examples/qtconcurrent/imagescaling/imagescaling.pro

@@ -5,5 +5,3 @@ HEADERS += imagescaling.h
 
 target.path = $$[QT_INSTALL_EXAMPLES]/qtconcurrent/imagescaling
 INSTALLS += target
-
-wince: DEPLOYMENT_PLUGIN += qgif qjpeg

examples/sql/sqlbrowser/sqlbrowser.pro

@@ -15,8 +15,3 @@ build_all:!build_pass {
 # install
 target.path = $$[QT_INSTALL_EXAMPLES]/sql/sqlbrowser
 INSTALLS += target
-
-
-wince {
-    DEPLOYMENT_PLUGIN += qsqlite
-}

examples/sql/sqlwidgetmapper/sqlwidgetmapper.pro

@@ -7,6 +7,4 @@ QT += sql widgets
 target.path = $$[QT_INSTALL_EXAMPLES]/sql/sqlwidgetmapper
 INSTALLS += target
 
-wince: DEPLOYMENT_PLUGIN += qsqlite
-
 

mkspecs/features/qt.prf

@@ -315,9 +315,7 @@ contains(TEMPLATE, .*app) {
     QTPLUGIN = $$manualplugs $$autoplugs
 }
 
-QT_PLUGIN_VERIFY = DEPLOYMENT_PLUGIN
 qtConfig(static) {
-    QT_PLUGIN_VERIFY += QTPLUGIN
     force_import_plugins|contains(TEMPLATE, .*app) {
         import_plugins:!isEmpty(QTPLUGIN) {
             IMPORT_FILE_CONT = \
@@ -337,10 +335,8 @@ qtConfig(static) {
             QMAKE_DISTCLEAN += $$IMPORT_CPP
         }
     }
-}
 
-for(QT_CURRENT_VERIFY, $$list($$QT_PLUGIN_VERIFY)) {
+    for (QTPLUG, $$list($$lower($$unique(QTPLUGIN)))) {
-    for(QTPLUG, $$list($$lower($$unique($$QT_CURRENT_VERIFY)))) {
        # Check if the plugin is known to Qt. We can use this to determine
        # the plugin path. Unknown plugins must rely on the default link path.
        QT_PLUGINPATH = $$eval(QT_PLUGIN.$${QTPLUG}.TYPE)
@@ -349,7 +345,7 @@ for(QT_CURRENT_VERIFY, $$list($$QT_PLUGIN_VERIFY)) {
         QT_LINKAGE = -l$${QTPLUG}$$qtPlatformTargetSuffix()
 
         # Only link against plugin in static builds
-        isEqual(QT_CURRENT_VERIFY, QTPLUGIN) {
+        {
             !isEmpty(QT_PLUGINPATH) {
                 plugpath = $$eval(QT_PLUGIN.$${QTPLUG}.PATH)
                 isEmpty(plugpath): \
@@ -357,21 +353,6 @@ for(QT_CURRENT_VERIFY, $$list($$QT_PLUGIN_VERIFY)) {
                 LIBS *= -L$$plugpath/$$QT_PLUGINPATH
             }
                 LIBS += $$QT_LINKAGE
-            # if the plugin is linked statically there is no need to deploy it
-            DEPLOYMENT_PLUGIN -= $$QT_CURRENT_VERIFY
-        }
-
-        # The following block is currently broken, because qt_plugin_XXX.prf files
-        # are not generated for dynamic builds.
-        false:isEqual(QT_CURRENT_VERIFY, DEPLOYMENT_PLUGIN):shared:winrt {
-            QT_ITEM =
-            debug: QT_ITEM = $${QTPLUG}d4.dll
-            else: QT_ITEM = $${QTPLUG}4.dll
-
-            qt_additional_plugin_$${QTPLUG}.files = $$[QT_INSTALL_PLUGINS/get]/$${QT_PLUGINPATH}/$${QT_ITEM}
-            qt_additional_plugin_$${QTPLUG}.path = $${QT_PLUGINPATH}
-
-            INSTALLS *= qt_additional_plugin_$${QTPLUG}
         }
     }
 }

qmake/doc/snippets/code/doc_src_qmake-manual.pro

@@ -784,10 +784,6 @@ CONFIG(debug, debug|release) {
 }
 #! [127]
 
-#! [142]
-DEPLOYMENT_PLUGIN += qjpeg
-#! [142]
-
 #! [149]
 SUBDIRS += my_executable my_library
 my_executable.subdir = app

qmake/doc/src/qmake-manual.qdoc

@@ -1119,24 +1119,6 @@
     Specifies a list of all directories to look in to resolve dependencies. This
     variable is used when crawling through \c included files.
 
-    \target DEPLOYMENT_PLUGIN
-    \section1 DEPLOYMENT_PLUGIN
-
-    \note This variable is used only on the Windows CE platform.
-
-    Specifies the Qt plugins that will be deployed. All plugins
-    available in Qt can be explicitly deployed to the device. See
-    \l{Static Plugins}{Static Plugins} for a complete list.
-
-    \note No plugins will be deployed automatically to Windows CE devices.
-    If the application depends on plugins, these plugins have to be specified
-    manually.
-
-    For example, the following definition uploads the jpeg imageformat plugin to
-    the plugins directory on the Windows CE device:
-
-    \snippet code/doc_src_qmake-manual.pro 142
-
     \target DESTDIR
     \section1 DESTDIR