support api initiated change_event for combox & textbox

Change-Id: Iff51a184792e9d12accb902df1772fc07589443b
diff --git a/vbahelper/source/msforms/vbacombobox.cxx b/vbahelper/source/msforms/vbacombobox.cxx
index 30f7237..6933884 100644
--- a/vbahelper/source/msforms/vbacombobox.cxx
+++ b/vbahelper/source/msforms/vbacombobox.cxx
@@ -120,7 +120,11 @@ void SAL_CALL
ScVbaComboBox::setValue( const uno::Any& _value ) throw (uno::RuntimeException)
{
    // booleans are converted to uppercase strings
    OUString oldValue = extractStringFromAny( getValue(), OUString(), true );
    m_xProps->setPropertyValue( sSourceName, uno::Any( extractStringFromAny( _value, OUString(), true ) ) );
    OUString newValue = extractStringFromAny( getValue(), OUString(), true );
    if ( oldValue != newValue )
        fireChangeEvent();
}

// see Value
diff --git a/vbahelper/source/msforms/vbatextbox.cxx b/vbahelper/source/msforms/vbatextbox.cxx
index d4d10c1..f61087e 100644
--- a/vbahelper/source/msforms/vbatextbox.cxx
+++ b/vbahelper/source/msforms/vbatextbox.cxx
@@ -59,6 +59,7 @@ ScVbaTextBox::getText() throw (css::uno::RuntimeException)
void SAL_CALL
ScVbaTextBox::setText( const OUString& _text ) throw (css::uno::RuntimeException)
{
    OUString oldText( getText() );
    if ( !mbDialog )
    {
        uno::Reference< text::XTextRange > xTextRange( m_xProps, uno::UNO_QUERY_THROW );
@@ -66,6 +67,8 @@ ScVbaTextBox::setText( const OUString& _text ) throw (css::uno::RuntimeException
    }
    else
        m_xProps->setPropertyValue( "Text" , uno::makeAny( _text ) );
    if ( oldText != _text )
        fireChangeEvent();
}

sal_Int32 SAL_CALL