Include urwid in the src.

Urwid is only be used for input, not display.
Now adding the minimal set of urwid modules that vigil needs.
These can be further pared down in future.

Thank you to Ian Ward.

urwid/compat.py

@@ -0,0 +1,37 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+#
+# Urwid python compatibility definitions
+#    Copyright (C) 2011  Ian Ward
+#
+#    This library is free software; you can redistribute it and/or
+#    modify it under the terms of the GNU Lesser General Public
+#    License as published by the Free Software Foundation; either
+#    version 2.1 of the License, or (at your option) any later version.
+#
+#    This library is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+#    Lesser General Public License for more details.
+#
+#    You should have received a copy of the GNU Lesser General Public
+#    License along with this library; if not, write to the Free Software
+#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# Urwid web site: http://excess.org/urwid/
+
+import sys
+
+
+PYTHON3 = sys.version_info > (3, 0)
+
+# for iterating over byte strings:
+# ord2 calls ord in python2 only
+# chr2 converts an ordinal value to a length-1 byte string
+# B returns a byte string in all supported python versions
+# bytes3 creates a byte string from a list of ordinal values
+ord2 = lambda x: x
+chr2 = lambda x: bytes([x])
+B = lambda x: x.encode('iso8859-1')
+bytes = bytes
+bytes3 = bytes