New option parameters

[Quantium]

Hi,

I'm added some parameters to work in a more flexible way with node-ab.

The new usage I'm proposing is something like this:

nab <URL> [--increase 100] [--milliseconds 1] [--help] [--verbose]

Some samples:
nab http://192.168.1.66
nab http://localhost
nab http://localhost:4000 --increase 200
nab http://localhost:4000 -i 200
nab http://localhost:4000 --milliseconds 1500
nab http://localhost:4000 --milliseconds 1500 --verbose
nab http://localhost:4000 -m 1500
nab http://localhost:4000 -m 1500 -v
nab --help
nab -h

[doubaokun]

Thanks for the commits.

[Quantium]

You're welcome.

I will add some functionalities soon.

I really use nab a lot.