chart2: ChartController: fix CommandDispatchContainer access locking

crashes on concurrent setModel() and getDispatchForURL() in
JunitTest_chart2_unoapi:

Thread 13:
 7  in (anonymous namespace)::Frame::isActionLocked (this=0x2b66c0e4a090) at /home/tinderbox/master/framework/source/services/frame.cxx:2596
 8  in (anonymous namespace)::Frame::close (this=0x2b66c0e4a090, bDeliverOwnership=0 '\000') at /home/tinderbox/master/framework/source/services/frame.cxx:1772
 9  in chart::ChartController::notifyClosing (this=0x2b668ae41058, rSource=...) at /home/tinderbox/master/chart2/source/controller/main/ChartController.cxx:872
 10 in apphelper::CloseableLifeTimeManager::impl_doClose (this=0x2b669a0b1d08) at /home/tinderbox/master/chart2/source/tools/LifeTime.cxx:360
 11 in apphelper::CloseableLifeTimeManager::g_close_endTryClose_doClose (this=0x2b669a0b1d08) at /home/tinderbox/master/chart2/source/tools/LifeTime.cxx:311
 12 in chart::ChartModel::close (this=0x2b669a0b1c28, bDeliverOwnership=1 '\001') at /home/tinderbox/master/chart2/source/model/main/ChartModel.cxx:659

Thread 1:
 4  in std::__debug::map<rtl::OUString, com::sun::star::uno::Reference<com::sun::star::frame::XDispatch>, std::less<rtl::OUString>, std::allocator<std::pair<rtl::OUString const, com::sun::star::uno::Reference<com::sun::star::frame::XDispatch> > > >::find (this=0x2b668ae41248, __x=...) at /usr/include/c++/4.8.3/debug/map.h:382
No locals.
 5  in chart::CommandDispatchContainer::getDispatchForURL (this=0x2b668ae41248, rURL=...) at /home/tinderbox/master/chart2/source/controller/main/CommandDispatchContainer.cxx:80
 6  in chart::ChartController::queryDispatch (this=0x2b668ae41058, rURL=..., rTargetFrameName=...) at /home/tinderbox/master/chart2/source/controller/main/ChartController.cxx:1003
No locals.
 7  in framework::DispatchProvider::implts_queryFrameDispatch (this=0x2b66a3fd21e8, xFrame=..., aURL=..., sTargetFrameName=..., nSearchFlags=0) at /home/tinderbox/master/framework/source/dispatch/dispatchprovider.cxx:374
 8  in framework::DispatchProvider::queryDispatch (this=0x2b66a3fd21e8, aURL=..., sTargetFrameName=..., nSearchFlags=0) at /home/tinderbox/master/framework/source/dispatch/dispatchprovider.cxx:111
 9  in framework::InterceptionHelper::queryDispatch (this=0x2b668a61bc08, aURL=..., sTargetFrameName=..., nSearchFlags=0) at /home/tinderbox/master/framework/source/dispatch/interceptionhelper.cxx:78
 10 in (anonymous namespace)::Frame::queryDispatch (this=0x2b66c0e4a090, aURL=..., sTargetFrameName=..., nSearchFlags=0) at /home/tinderbox/master/framework/source/services/frame.cxx:2227
 11 in svt::ToolboxController::bindListener (this=0x2b66c0f72740) at /home/tinderbox/master/svtools/source/uno/toolboxcontroller.cxx:529
 12 in svt::ToolboxController::update (this=0x2b66c0f72740) at /home/tinderbox/master/svtools/source/uno/toolboxcontroller.cxx:232
 13 in framework::ToolBarManager::UpdateControllers (this=0x2b669a0a1728) at /home/tinderbox/master/framework/source/uielement/toolbarmanager.cxx:440
 14 in framework::ToolBarManager::AsyncUpdateControllersHdl (this=0x2b669a0a1728) at /home/tinderbox/master/framework/source/uielement/toolbarmanager.cxx:2110
 15 in framework::ToolBarManager::LinkStubAsyncUpdateControllersHdl (pThis=0x2b669a0a1728, pCaller=0x2b669a0a1890) at /home/tinderbox/master/framework/source/uielement/toolbarmanager.cxx:2097
 16 in Link::Call (this=0x2b669a0a18b0, pCaller=0x2b669a0a1890) at /home/tinderbox/master/include/tools/link.hxx:139
 17 in Timer::Timeout (this=0x2b669a0a1890) at /home/tinderbox/master/vcl/source/app/timer.cxx:276

Change-Id: I17ef63db8f7c288460e00031e8e8a5c3e4d086b3
svl: SfxItemSet: get rid of the "no master pool" warning spam

No idea why that would be a problem.

Change-Id: Ib655b71ed8cd8a4fe8200209c929434832f3614e