Mark QNX plugin as experimental for now, just like the Android plugin.

It will still be built to ensure inclusion in the QA process and to
avoid build breakage, but will not be loaded by default.

Change-Id: I9b5253d6f1b1174f8c4226febaa3559dc9bd60d5
Reviewed-by: Daniel Teske <daniel.teske@nokia.com>

src/plugins/qnx/Qnx.pluginspec.in

-<plugin name=\"Qnx\" version=\"$$QTCREATOR_VERSION\" compatVersion=\"$$QTCREATOR_VERSION\">
+<plugin name=\"Qnx\" version=\"$$QTCREATOR_VERSION\" compatVersion=\"$$QTCREATOR_VERSION\" experimental=\"$$QNX_EXPERIMENTAL_STR\">
     <vendor>Research In Motion</vendor>
     <copyright>(C) Research In Motion</copyright>
     <license>

src/plugins/qnx/qnx.pro

@@ -3,6 +3,9 @@ TARGET = Qnx
 QT += network xml
 PROVIDER = RIM
 
+isEmpty(QNX_ENABLE):QNX_EXPERIMENTAL_STR="true"
+else:QNX_EXPERIMENTAL_STR="false"
+
 include(../../qtcreatorplugin.pri)
 include(qnx_dependencies.pri)