ntopng 1.1.4 (new Formula)

Hi,

This is a new Formula for [ntopng](http://www.ntop.org/products/ntop/). 

Let me know if there is any problem.

Thanks,
Filippo

Can this test be modified to do something more substantial then e.g. `--version` or `--help`? See `cmake.rb` for an example of a formula with a good test. Thanks!