Merge SOC2009_FSWATCHER branch into trunk.

Merges everything from the branch with only some minor changes, mostly renamed
wxUSE_FSWATCHER_{INOTIFY,KQUEUE} to wxHAS_{INOTIFY,KQUEUE}.

Add wxFileSystemWatcher and related classes.

Also introduces wxEventLoopSource.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@62474 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/evtloopcmn.cpp

@@ -54,6 +54,11 @@ void wxEventLoopBase::OnExit()
 {
     if (wxTheApp)
         wxTheApp->OnEventLoopExit(this);
+
+#if wxUSE_EVENTLOOP_SOURCE
+    // unregister all sources
+    (void) RemoveAllSources();
+#endif
 }
 
 void wxEventLoopBase::WakeUpIdle()