tdf#115430 BindDispatch_Impl needs a disposal method

The dtor will never be called otherwise, because the
dispatcher is holding a reference to us, so
removeStatusListener is needed first.

Regression of a5dbe5a8
("use rtl::Reference in svl,sfx2")

Change-Id: I52da6152f0ddb0030d7354f7201e969d5a1f11cf
Reviewed-on: https://gerrit.libreoffice.org/49423Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Maxim Monastirsky <momonasmon@gmail.com>

sfx2/source/control/bindings.cxx

@@ -1604,6 +1604,7 @@ SfxItemState SfxBindings::QueryState( sal_uInt16 nSlot, std::unique_ptr<SfxPoolI
                 }
 
                 xDisp->removeStatusListener( xBind.get(), aURL );
+                xBind->Release();
                 xBind.clear();
                 if ( bDeleteCache )
                     DELETEZ( pCache );

sfx2/source/control/statcach.cxx

@@ -145,13 +145,14 @@ void SAL_CALL  BindDispatch_Impl::statusChanged( const css::frame::FeatureStateE
     }
 }
 
-BindDispatch_Impl::~BindDispatch_Impl()
+void BindDispatch_Impl::Release()
 {
     if ( xDisp.is() )
     {
         xDisp->removeStatusListener( static_cast<css::frame::XStatusListener*>(this), aURL );
         xDisp.clear();
     }
+    pCache = nullptr;
 }
 
 
@@ -197,6 +198,8 @@ SfxStateCache::~SfxStateCache()
     DBG_ASSERT( pController == nullptr && pInternalController == nullptr, "there are still Controllers registered" );
     if ( !IsInvalidItem(pLastItem) )
         delete pLastItem;
+    if ( mxDispatch.is() )
+        mxDispatch->Release();
 }
 
 
@@ -208,6 +211,8 @@ void SfxStateCache::Invalidate( bool bWithMsg )
     {
         bSlotDirty = true;
         aSlotServ.SetSlot( nullptr );
+        if ( mxDispatch.is() )
+            mxDispatch->Release();
         mxDispatch.clear();
     }
 }

sfx2/source/inc/statcach.hxx

@@ -46,13 +46,13 @@ public:
                                 const css::uno::Reference< css::frame::XDispatch > & rDisp,
                                 const css::util::URL& rURL,
                                 SfxStateCache* pStateCache, const SfxSlot* pSlot );
-                            ~BindDispatch_Impl() override;
 
     virtual void SAL_CALL   statusChanged( const css::frame::FeatureStateEvent& Event ) override;
     virtual void SAL_CALL   disposing( const css::lang::EventObject& Source ) override;
 
     const css::frame::FeatureStateEvent& GetStatus() const { return aStatus;}
     sal_Int16               Dispatch( const css::uno::Sequence < css::beans::PropertyValue >& aProps, bool bForceSynchron );
+    void                    Release();
 };
 
 class SfxStateCache