This patch changes LO behavior so that we update recent documents on file save, save as, save all, and close. The previous behavior was to only update the list on document close.

= Changes =
SfxPickList (sfxpicklist.cxx/hxx):
    . Extracted the logic to add a document to the "Recent Documents" list into a function of its own: AddDocumentToPickList
        - Simplified the logic used by removing the check of SfxObjectShell_impl::bWaitingForPickList (see SfxObjectShell_impl::bWaitingForPickList below for details)
    . Modified SfxPickList::Notify to call the aforementioned function on save, save-to, and save-as.

SfxObjectShell::APISaveAs_Impl (objserv.cxx):
    . Modified it to allow picklist entry when doing "Save As".

SfxObjectShell_impl::bWaitingForPickList (objstor.cxx, objxtor.cxx, objshimp.hxx):
    . Removed this flag. It was used to indicate that a document wants to be added to the picklist, then cleared after it's added. Since we now always add documents to the picklist on saving, we no longer need it.

= Verification =
The change is in sfx2, so it should apply to all LO apps. I verified the new behavior in both writer and calc with the following actions:
    . File->Save
    . File->Save As
    . File->Save All
    . File->Close