Add an animation to comfort the user

Sometimes msfconsole takes a little while to start.

This adds a fairly common ASCII spinner to the startup sequence.

I haven't spec'ed it, and the code organization isn't great, so consider
this PR more of a cry for help than something immediately landable.

That said, it works for me.
No need for that bool option
-q will quiet the animation, too
Control the startup msg with -q, too
@wvu-r7 is a skilled negotiator. s/stdout/stderr/
Land #4014, msfconsole spinnerz