rem: void KMSortCacheItem::updateSortFile(FILE *sortStream, bool waiting_for_parent)
add: void KMSortCacheItem::updateSortFile(FILE *sortStream, KMFolder *folder, bool waiting_for_parent)
context: void KMSortCacheItem::updateSortFile(FILE *sortStream, bool waiting_for_parent){    if(mSortOffset == -1) {	fseek(sortStream, 0, SEEK_END);	mSortOffset = ftell(sortStream);    } else {	fseek(sortStream, mSortOffset, SEEK_SET);    }    int parent_id = -2;    if(!waiting_for_parent) {	if(mParent)	    parent_id = mParent->id();	else	    parent_id = -1;    }    internalWriteItem(sortStream, mId, parent_id, mKey);}