Remove the instance with `id`

Property definitions

	# Remove the instance with `id`
	fun remove_by_id(id: String): Bool is abstract

lib/popcorn/pop_repos.nit:192,2--193,47

	redef fun remove_by_id(id) do
		var query = new JsonObject
		query["_id"] = id
		return remove(query)
	end

lib/popcorn/pop_repos.nit:347,2--351,4