Proposal for removedFromContext method in BrowserPage

[webfirmframework]

Currently, the way to track if a BrowserPage instance is removed from BrowserPageContext is writing code inside session close listener.
When BrowserPageContext.INSTANCE.httpSessionClosed(session.getId()); is called inside session close listener all BrowserPage instances under that session will be removed from context. And using BrowserPageContext.INSTANCE.getBrowserPages(httpSessionId) all browserPages under that session can be retrieved before invoking httpSessionClosed.

For better convenience of the developer :-
Proposing a overriding method removedFromContext in BrowserPage which will be executed when the BrowserPage instances is removed from BrowserPageContext.

[webfirmframework]

There is implemented an overridden method removedFromContext in BrowserPage which will get invoked when the browserPage is removed from BrowserPageContext. It will be available in the next version.