Add Apache license header to all rst documentation

This patch has the Apache license header found in
doc/source/dev/glossary.rst added to every .rst file

Change-Id: Icc20e7baf7d3cd0f116c371d54ef03c7c8401778
Closes-Bug: #1523986

HACKING.rst

@@ -1,3 +1,16 @@
+..
+      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.
+
 ==========================
 watcher Style Commandments
 ==========================