Add reconnect_wait_max, and reconnect_wait_incr_rate options

Added options to configure RECONNECT_WAIT_MAX, and RECONNECT_WAIT_INCR_RATE.

I added following options to bin/fluent-agent-lite, and still wondering for `-r`. Any opinions?

```
-w RECONNECT_WAIT_MAX
-r RECONNECT_WAIT_INCR_RATE
```