Restore --print-found option.

Now --print-all and --print-found complement each other.  The default remains that only the found are reported.

sherlock/sherlock.py

@@ -476,9 +476,13 @@ def main():
                              "On the other hand, this may cause a long delay to gather all results."
                         )
     parser.add_argument("--print-all",
-                        action="store_true", dest="print_all", default=False,
+                        action="store_true", dest="print_all",
                         help="Output sites where the username was not found."
                        )
+    parser.add_argument("--print-found",
+                        action="store_false", dest="print_all", default=False,
+                        help="Output sites where the username was found."
+                       )
     parser.add_argument("--no-color",
                         action="store_true", dest="no_color", default=False,
                         help="Don't color terminal output"