This commit consists of:
1) Add session management to netconf
2) Modularize the rpc call
3) Improve the error handling
4) Small bug fixes

Change-Id: I023edb76e3743b633ac87be4967d656e09e2b970
diff --git a/netconf/session/session.py b/netconf/session/session.py
new file mode 100644
index 0000000..51979f7
--- /dev/null
+++ b/netconf/session/session.py
@@ -0,0 +1,28 @@
+#!/usr/bin/env python
+#
+# Copyright 2016 the original author or authors.
+#
+# 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
+#
+# 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.
+#
+from time import time
+import structlog
+
+log = structlog.get_logger()
+
+
+class Session:
+    def __init__(self, session_id, user):
+        self.session_id = session_id
+        self.user = user
+        self.started_at = time()
+        self.session_opened = False