dump: add dump pass

I use it a while now but forgot to add it to the git.

Signed-off-by: Marek Chalupa <mchqwerty@gmail.com>
wldbg: handle signals

Handle interrupt signal and SIGCHLD.
wldbg: add missing new line
wldbg: add one-by-one mode

In this mode, wldbg reads connection and split incoming data
into messages. Each message is then processed and resend separately.

User cannot turn it on now (no arg switch for that), but this
is on TODO list.

Signed-off-by: Marek Chalupa <mchqwerty@gmail.com>
saviour