Rather than telling the client to exit in the function when creating a new session detached, let the caller do it. Allows "tmux new -d \; attach" to work.
Rather than telling the client to exit in the function when creating a new
session detached, let the caller do it. Allows "tmux new -d \; attach" to work.

klaxalk/tmux,klaxalk/tmux,klaxalk/tmux,klaxalk/tmux,klaxalk/tmux