Implement IWebHistoryItem::[set]AlternateTitle

Implement IWebHistoryItem::[set]AlternateTitle

WebCore:

        Add an assignment operator for BString that takes a BSTR

        Reviewed by Geoff and Oliver.

        * platform/win/BString.cpp:
        (WebCore::BString::operator=):
        * platform/win/BString.h:

WebKit/win:

        Implement IWebHistoryItem::[set]AlternateTitle

        The argument types were reversed for these two methods, so I fixed that as
        well.

        Reviewed by Geoff and Oliver.

        * Interfaces/IWebHistoryItem.idl:
        * WebHistoryItem.cpp:
        (WebHistoryItem::setAlternateTitle): Implemented.
        (WebHistoryItem::alternateTitle): Implemented.
        * WebHistoryItem.h:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@24562 268f45cc-cd09-0410-ab3c-d52691b4dbfc