Export the symbols of libdbus-1 when loading it at runtime.

This allows applications that need additional symbols from the library to
easily obtain them without needing to replicate the library open logic
from qdbus_symbols.cpp.

Change-Id: Ic65ef6684637fbcd1c9f4fe1dc7a57f0624b61a8
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/dbus/qdbus_symbols.cpp

@@ -81,6 +81,7 @@ bool qdbus_loadLibDBus()
         return lib && lib->isLoaded();
 
     lib = new QLibrary;
+    lib->setLoadHints(QLibrary::ExportExternalSymbolsHint); // make libdbus symbols available for apps that need more advanced control over the dbus
     triedToLoadLibrary = true;
 
     static int majorversions[] = { 3, 2, -1 };