Support a configurable default report

[pbeckingham]

Currently a brief summary of an active interval is displayed when the command timew is entered. This could be configurable, so that other commands could run.

[lauft]

Are you thinking of an entry point for a hook?

[pbeckingham]

Well, the original intent was to allow either the current "last interval state" report, or summary, or any other report be the one that runs when you enter "timew" with no command.