paclog: add --before and --after filters

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>
paclog: read log from stdin

This allows multiple calls to be chained together.

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>
paclog: document --before/--after

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>
paclog: fix tabs from overzealous +retab

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>
paclog: print entire log with no filters

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>
paclog: color output

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>