Add API Reference for Watcher

This patch set adds API Reference along with some
fixes to documentation. It partially fixes bug #1757423.

Change-Id: I107b4fd5daf40aad63fc13864debbbbc82a9826c

api-ref/source/watcher-api-v1-goals.inc

@@ -0,0 +1,126 @@
+.. -*- rst -*-
+
+=====
+Goals
+=====
+
+A ``Goal`` is a human readable, observable and measurable end result having
+one objective to be achieved.
+
+Here are some examples of ``Goals``:
+
+-  minimize the energy consumption
+-  minimize the number of compute nodes (consolidation)
+-  balance the workload among compute nodes
+-  minimize the license cost (some softwares have a licensing model which is
+   based on the number of sockets or cores where the software is deployed)
+-  find the most appropriate moment for a planned maintenance on a
+   given group of host (which may be an entire availability zone):
+   power supply replacement, cooling system replacement, hardware
+   modification, ...
+
+List Goal
+=========
+
+.. rest_method::  GET /v1/goals
+
+Returns a list of Goal resources.
+
+Normal response codes: 200
+
+Error codes: 400,401
+
+Request
+-------
+
+.. rest_parameters:: parameters.yaml
+
+   - limit: limit
+   - sort_dir: sort_dir
+   - sort_key: sort_key
+
+Response
+--------
+
+.. rest_parameters:: parameters.yaml
+
+    - uuid: uuid
+    - efficacy_specification: goal_efficacy_specification
+    - name: goal_name
+    - display_name: goal_display_name
+    - links: links
+
+**Example JSON representation of a Goal:**
+
+.. literalinclude:: samples/goal-list-response.json
+   :language: javascript
+
+List Goal Detailed
+==================
+
+.. rest_method::  GET /v1/goals/detail
+
+Returns a list of Goal resources with complete details.
+
+Normal response codes: 200
+
+Error codes: 400,401
+
+Request
+-------
+
+.. rest_parameters:: parameters.yaml
+
+   - limit: limit
+   - sort_dir: sort_dir
+   - sort_key: sort_key
+
+Response
+--------
+
+.. rest_parameters:: parameters.yaml
+
+    - uuid: uuid
+    - efficacy_specification: goal_efficacy_specification
+    - name: goal_name
+    - display_name: goal_display_name
+    - links: links
+
+**Example JSON representation of a Goal:**
+
+.. literalinclude:: samples/goal-list-response.json
+   :language: javascript
+
+Show Goal
+=========
+
+.. rest_method::  GET /v1/goals/{goal_ident}
+
+Shows details for an Goal.
+
+Normal response codes: 200
+
+Error codes: 404
+
+Request
+-------
+
+.. rest_parameters:: parameters.yaml
+
+   - goal_ident: goal_ident
+
+Response
+--------
+
+.. rest_parameters:: parameters.yaml
+
+    - uuid: uuid
+    - efficacy_specification: goal_efficacy_specification
+    - name: goal_name
+    - display_name: goal_display_name
+    - links: links
+
+**Example JSON representation of a Goal:**
+
+.. literalinclude:: samples/goal-show-response.json
+   :language: javascript