adds python implementations

- more README
- fix some C++ code along the way

pcat.py

@@ -1,8 +1,11 @@
-#!/usr/bin/env python3
-#
+#!/usr/bin/env python
+
 import sys
 
-while True:
-    with open(sys.argv[1],'r') as fd:
-        print(fd.read(), flush=True)
+if __name__ == "__main__":
+
+    while True:
+        with open(sys.argv[1]) as fin:
+            line = fin.readline()
+        sys.stdout.write(line)