Fixes #1133 (#1142)
Fixes #1133 (#1142)

Fixing memory leak from ComboBoxPopup registering itself as a DP callback. Switching to simply overriding the OnPropertyChanged method to avoid accidently capturing our instance in the delegate.
ButchersBoy/MaterialDesignInXamlToolkit,ButchersBoy/MaterialDesignInXamlToolkit,ButchersBoy/MaterialDesignInXamlToolkit