crit: Get rid of --format option

I plan to mark some fields as IP address and print them respectively.
The --format hex is not nice switch for this and introducing one more
(--format hex ipadd) is too bad.

So let's fix the cirt API to be simple and stupid. By default crit
generates canonical one-line JSON. With --pretty option it splits the
output into lines, adds indentation and prints hex as hex and IP as
IP.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Ruslan Kuprieiev <kupruser@gmail.com>