Fixed crash that occurs after clicking on 'History' button

Fixed crash that occurs after clicking on 'History' button

[Issue#]    https://bugs.tizen.org/jira/browse/TT-98
[Problem]   Browser crashes after clicking on 'History' button.
[Cause]     There was used normal pointer that pointed to the destroyed object.
[Sollution] 1. Changed type of HistoryService::getHistoryItems() and
            HistoryService::getMostVisitedHistoryItems() functions that the return
            std::shared_ptr<std::vector<std::shared_ptr<HistoryItem> > >.
            2. Added HistoryService::getHistoryItem function which returns HistoryItem by id.
            3. Added HistoryService::getCurrentTab functions that returns currently
            observed web page's info.
            4. Changed type of h_item pointer in MoreMenuUI.cpp from normal pointer to
            shared_ptr.
            5. Added listItemDel function to avoid memory leaks when genlist is cleared.
[Verify]    Launch browser > More Menu > History > Obs
            History should not crash after clicking on 'History' button.

Change-Id: I9140c1dedc061b2d014792aa14da92053e7aa27f