Merge fixes from cloud_sync branch.

Signed-off-by: Rob Caelers <robc@krandor.org>
Fix gtk2 win32 compilation.

Signed-off-by: Rob Caelers <robc@krandor.org>
Merge branch 'master' of ../workrave into topic_cloud_sync

Conflicts:
	frontend/common/include/System.hh
	frontend/common/include/TimerBoxControl.hh
	frontend/gtkmm/src/GnomeAppletMenu.hh
	frontend/gtkmm/src/HeadInfo.hh
	frontend/gtkmm/src/Hig.hh
	frontend/gtkmm/src/IBreakWindow.hh
	frontend/gtkmm/src/IMenu.hh
	frontend/gtkmm/src/IPreludeWindow.hh
	frontend/gtkmm/src/IconListCellRenderer.cc
	frontend/gtkmm/src/IconListCellRenderer.hh
	frontend/gtkmm/src/MainGtkMenu.hh
	frontend/gtkmm/src/MenuBase.hh
	frontend/gtkmm/src/PreludeWindow.cc
	frontend/gtkmm/src/WindowHints.cc
	frontend/plugin/distribution/gtkmm/src/NetworkPreferencePage.cc
	frontend/plugin/exercises/common/src/Exercise.hh