Licensing

This project is now licensed under the Apache license. Individual files
now have a license reference header.

The Apache 2.0 license text is copied to the file LICENSE. The file
NOTICE, referred to in the license text, has been added. A placeholder
README.txt has been added.

These three new files are integrated into the distribution/installation
machinery, and are placed into the package directory upon installation.

dtls/__init__.py

@@ -1,4 +1,21 @@
-# PyDTLS: datagram TLS for Python. Written by Ray Brown.
+# PyDTLS: datagram TLS for Python.
+
+# Copyright 2012 Ray Brown
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# The License is also distributed with this work in the file named "LICENSE."
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 """PyDTLS package
 
 This package exports OpenSSL's DTLS support to Python. Calling its patch