Set python package version from C header

setup.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python
 
+from re import findall
 from os import path
 from io import open
 try:
@@ -10,10 +11,14 @@
 here = path.abspath(path.dirname(__file__))
 with open(path.join(here, 'README.md'), encoding='utf-8') as f:
     long_description = f.read()
+with open(path.join(here, 'include/graphite2/Font.h')) as f:
+    c_header = f.read()
+major, minor, bug = findall('define GR2_VERSION_[A-X]+\s+(\d+)', c_header)
+version = major + "." + minor + "." + bug
 
 setup(
     name             = 'graphite2',
-    version          = '1.3.11',
+    version          = version,
     description      = 'SIL graphite2 smart font system python bindings',
     author           = 'SIL International',
     license          = 'LGPL-2.1+ OR MPL-1.1+',