Git: use a ridiculously obvious interactive prompt color

It's possible that this is even too strong (I might want to swap out the
"reverse" for "ul" if this proves to be too much of an eyesore; but note
that "bold" is next to useless on this terminal), but I find it tiresome
when working my way through a long run of hunks in `git add --patch` to
have to visually scan upwards to where the previous hunk ends and the
current one begins.

This makes the prompts so strident that it is impossible to not see
them, and makes it very clear where the hunks begin and end.

Tested with Solarized light and dark.

Signed-off-by: Wincent Colaiuta <win@wincent.com>
Git: lower help.autocorrect interval

When I originally set this to 10 (ie. 1 second) I wanted an interval
that was long enough to notice, but not too long to become annoying, and
at the same time just long enough that I could Control-C if I saw that
it was about to do something really stupid that I wanted to abort.

Having had the setting in place for a couple of years now, I doubt I've
even tried to abort a command more than half-a-dozen times (and that is
a generous estimate).

So, I'm lowering the interval. 0.2 seconds is definitely long enough to
notice that something happened, but not so long that you have time to
think, "Oh come on, hurry up and move on now".

Signed-off-by: Wincent Colaiuta <win@wincent.com>