whatchanged: document its historical nature
whatchanged: document its historical nature

Encourage new users to use 'log' instead.  These days, these
commands are unified and just have different defaults.

'git log' only allowed you to view the log messages and no diffs
when it was added in early June 2005.  It was only in early April
2006 that the command learned to take diff options.  Because of
this, power users tended to use 'whatchanged' that already existed
since mid May 2005 and supported diff options.

Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git