Fixed some copyright and readme inconsistentcies.

README.md

 ```text
 slop v3.1.4
 
-Copyright (C) 2014 Dalton Nell, GPLv3
+Copyright (C) 2014 Dalton Nell, Slop Contributors (https://github.com/naelstrof/slop/graphs/contributors)
 
 Usage: slop [options]
 

cmdline.c

 
 const char *gengetopt_args_info_usage = "Usage: slop [options]";
 
-const char *gengetopt_args_info_versiontext = "Copyright (C) 2014 Dalton Nell, GPLv3";
+const char *gengetopt_args_info_versiontext = "Copyright (C) 2014 Dalton Nell, Slop Contributors\n(https://github.com/naelstrof/slop/graphs/contributors)";
 
 const char *gengetopt_args_info_description = "slop (Select Operation) is an application that queries for a selection from the\nuser and prints the region to stdout.";
 

options.ggo

 version "v3.1.4"
 usage "slop [options]"
 description "slop (Select Operation) is an application that queries for a selection from the user and prints the region to stdout."
-versiontext "Copyright (C) 2014 Dalton Nell, GPLv3"
+versiontext "Copyright (C) 2014 Dalton Nell, Slop Contributors (https://github.com/naelstrof/slop/graphs/contributors)"
 
 text "Options"