Fixes #7 : Add drop privileges function

[namay26]

Drops the root privileges once Glutton has set up IPTables.

Glutton now has privileges of the nobody user.

[glaslos]

What is your opinion on the discussion in this PR? #175

[namay26]

I didn't consider the shutdown process. On reading more about it, the only work around I could find is to have another process -- A helper process -- which runs with root privileges and handles the flushing of IP Tables.
I was trying to work around with Real and Effective UIDs but Unix system don't allow to go back to escalated privileges.
What do you suggest?

[namay26]

I am able to successfully drop privileges during the routine operation of the honeypot while maintaining the root access for IPTables Management.

I was able to shutdown without any error. This adds complexity as the initial process has to be forked but does the required work.
@glaslos

[glaslos]

Please rebase the PR

[glaslos]

Are you sure the iptables rules are dropped?

[namay26]

This doesn't work, the go routines don't retain the privilege once the process drops it.
We will have to fork the process and then drop the privileges while managing the IP tables in the other process.
Is this something that you're open to? ^

[glaslos]

Let's close this PR. I don't think we will benefit much if we can't fully drop the privileges.