Memory leak when pasting in vxfw

[timeopochin]

As mentioned in #251, because the paste event is not handled in vxfw widgets, the text is never freed. I'm not sure what the best way to resolve this would be. No widgets use the paste event, so removing it fixes the problem. But future or custom widgets might want that functionality.

[spicydll]

I fix this in PR #263 . This was also an issue when using setTitle