Curlbomb

* Adds --log paramater to log messages to file instead of stdout.
* Print client command to stdout when pipeing curlbomb output, unless
-l is specified, then no client command is printed.
* Subcommands inherit all the curlbomb arguments. 'curlbomb -l run'
is now equivalent to 'curlbomb run -l'
* Improves --help by organizing parameters into groups
* Moves all subcommands to a subcommands module

* Fixes run --signature to better handle the capturing of who the
signature is from from the gpg output. This was only giving false
negatives.

* Fixes socket closing issues on shutdown by polling for open sockets
with psutil before shutdown.
* --log-posts is only turned on explicity. Prior to 1.4.0 it was
turned on automatically when pipeing output. This was just
confusing.
* Adds run --hash argument to require a specific SHA256 of the input
script.
* Adds run --signature argument require that the input script match
the given gpg signature file.
* Removes -1 and --disable-postback. Both are now the default. Use -l
if you want to wait for the client to finish.
* Fixes scripts that need an interactive tty. Use --pipe.
* run SCRIPT can now be a URL in addition to a file path.
* --ssl now always requires a CERTIFICATE. You must specify the cert
as '-' if you want to use self-signed auto-generated certificate.
* Adds --encrypt, --passphrase, and --encrypt-to options for GPG
encryption of the resource.

* Adds path to curlbomb python modules in --version output.
* Allow HTTP HEAD requests to / and /r without increasing num_gets or
requiring a knock.
* Outputs warning message if using --ssh and the forward isn't working
* --ssl can be used with specifing a CERTIFICATE path, in this case
generating a temporary self-signed cert.
* Adds --pin parameter to give the client curl command the SSL fingerprint
bypassing the client machine's root CA.

* Modular rewrite - the single .py file was getting a wee bit unwieldy
* Adds ping subcommand
* Adds ssh-copy-id subcommand
* Adds support for loading GPG encrypted scripts into the server
* Adds ability to specify your own knock parameter with --knock
* Fixes '-n 0' to serve a script an unlimited number of times
* Adds -1 paramater as a one-shot curlbomb that does not wait for client output
* Removes the -k option to have no knock. It was a bad idea to use a
short option for that and it had a counter-intuitive mnemonic. Use
--disable-knock now, or even better, use the --knock parameter and
specify an easy-to-remember knock.

* Adds put/get subcommands for transferring files and directories.
* Adds run subcommand for running scripts, but only required if
specifying a file path, can still pipe data to curlbomb without
args.