Bookmark API: cursor interface for Get Bookmarks

[jpowerwa]

Implement cursor for Get Bookmarks; i.e. caller specifies start item id and max number of desired items, or page number and items-per-page, and response includes information about total number of items. Details to be provided in API spec.

[yakticus]

I've added the query cursor to the GET API in my branch, not sure if this includes everything you describe above.