Add a feature for Qt Network

This way you can disable support for QtNetwork by specifying
-no-feature-network on the configure line.

Change-Id: I46217ccc525a9e2c85394ed4eb6db0e2b60b6d86
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@qt.io>

configure.json

@@ -930,6 +930,10 @@
                 { "type": "publicQtConfig", "negative": true }
             ]
         },
+        "network": {
+            "label": "Qt Network",
+            "output": [ "privateFeature" ]
+        },
         "widgets": {
             "label": "Qt Widgets",
             "condition": "features.gui",
@@ -1123,6 +1127,7 @@ Configure with '-qreal float' to create a build that is binary-compatible with 5
                 "dbus",
                 "dbus-linked",
                 "gui",
+                "network",
                 "widgets"
             ]
         }, {

src/src.pro

@@ -124,7 +124,7 @@ src_printsupport.depends = src_corelib src_gui src_widgets src_tools_uic
 
 src_plugins.subdir = $$PWD/plugins
 src_plugins.target = sub-plugins
-src_plugins.depends = src_sql src_xml src_network
+src_plugins.depends = src_sql src_xml
 
 src_android.subdir = $$PWD/android
 
@@ -144,7 +144,11 @@ qtConfig(regularexpression):pcre {
 SUBDIRS += src_corelib src_tools_qlalr
 TOOLS = src_tools_moc src_tools_rcc src_tools_qlalr
 win32:SUBDIRS += src_winmain
-SUBDIRS += src_network src_sql src_xml src_testlib
+SUBDIRS += src_sql src_xml src_testlib
+qtConfig(network) {
+    SUBDIRS += src_network
+    src_plugins.depends += src_network
+}
 qtConfig(dbus) {
     force_dbus_bootstrap|qtConfig(private_tests): \
         SUBDIRS += src_tools_bootstrap_dbus