Update Sphinx version and versioning process

- Updated to newer Sphinx version
- Changed to use doc8 to check .rst files
- Added a dictionary (dict.txt) and spellchecking
- Reformatted and fixed issues that were found in the content

Change-Id: If7b35e01ee8be25dbbd1ecd0e67b264aa6cc2a94
diff --git a/specification.rst b/specification.rst
index cde9dd2..f221380 100644
--- a/specification.rst
+++ b/specification.rst
@@ -4,13 +4,14 @@
 
 SDN Features
 ============
+
   - ONOS cluster of all-active N instances affording N-way redundancy and scale, where N = 3 or N = 5.
   - Unified operations interface (GUI/REST/CLI)
   - Centralized configuration – all configuration is done on controller instead of each individual switch
   - Centralized role-based access control (RBAC)
   - Automatic host (end-point) discovery – attached hosts, access-devices, appliances (PNFs), routers, etc.
   - based on ARP, DHCP, NDP, etc.
-  - Automatic switch, link and topology discovery and maintenance (keep-alives, failure recovery)
+  - Automatic switch, link and topology discovery and maintenance (keepalive, failure recovery)
 
 L2 Features
 ===========
@@ -145,6 +146,10 @@
 Whitebox Switch Software
 ========================
   - Open source ONL, ONIE and Indigo OF client
+
   - (in production) OF-DPA software commercial version – contact Broadcom
-  - (in labs/trials) OF-DPA software community version available from ONF (for switch models based on Trident and Tomahawk, not Qumran)
-  - (in labs/trails) Stratum available from ONF
\ No newline at end of file
+
+  - (in labs/trials) OF-DPA software community version available from ONF (for
+    switch models based on Trident and Tomahawk, not Qumran)
+
+  - (in labs/trails) Stratum available from ONF