docs: generate the value for release from ../configure/CONFIG

documentation/conf.py

@@ -11,7 +11,7 @@
 # All configuration values have a default; values that are commented out
 # serve to show the default.
 
-import sys, os
+import sys, os, re
 
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
@@ -51,8 +51,15 @@ copyright = u"""
 #
 # The short X.Y version.
 version = '2.1'
+
+def get_seq_release():
+  for line in open('../configure/CONFIG').readlines():
+    m = re.match('\s*SEQ_RELEASE\s*=\s*([^\s]+)', line)
+  if m is not None:
+    return m.group(1)
+
 # The full version, including alpha/beta/rc tags.
-release = '2.1.13'
+release = get_seq_release()
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.