Read version from source code; add --version; try protect my email from spambot

CHANGES

 Change log
 ==========
 
+Version 0.1 (2013-02-05)
+
+    - New --version option
+    - setup.py now read version from source code
+
 Version 0.0.4 (2013-02-04)
 
   - Add CHANGES for history track and better versioning

LICENSE

 Software License Agreement (BSD-3 License)
 
-Copyright (c) 2013, Matthew Wang <mattwyl@gmail.com>
+Copyright (c) 2013, Matthew Wang <mattwyl(@)gmail(.)com>
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without modification,

README.rst

     git log -p -2 | cdiff -s
     git show 15bfa56 | cdiff -s
     svn diff -r PREV | cdiff -s
+    diff -u foo foo.new | cdiff -s
 
 Redirect output to another patch file is safe:
 

setup.py

     os.unlink(link_name)
 os.symlink('src/cdiff.py', link_name)
 
-with open('CHANGES') as changes:
-    for change in changes:
-        if change.startswith('Version '):
-            version = change.split()[1]
+# This awfulness is all in aid of grabbing the version number out
+# of the source code, rather than having to repeat it here.  Basically,
+# we parse out firt line starts with "__version__" and execute it
+#
+with open('cdiff') as script:
+    for line in script:
+        if line.startswith('__version__ = '):
+            exec(line)
             break
-    changes.seek(0)
-    with open('README.rst') as doc:
-        long_description = doc.read() + changes.read()
+
+with open('README.rst') as doc:
+    long_description = doc.read()
+with open('CHANGES') as changes:
+    long_description += changes.read()
 
 setup(
     name = 'cdiff',
-    version = version,
+    version = __version__,
     author = 'Matthew Wang',
-    author_email = 'mattwyl@gmail.com',
+    author_email = 'mattwyl(@)gmail(.)com',
     license = 'BSD-3',
     description = ('Term based tool to view colored, incremental diff in '
-                   'unified format or side ' 'by side with auto pager'),
+                   'unified format or side by side with auto pager'),
     long_description = long_description,
     keywords = 'colored incremental side-by-side diff',
     url = 'https://github.com/ymattw/cdiff',

src/cdiff.py

 # -*- coding: utf-8 -*-
 
 """
-View colored, incremental diff in unified format or in side by side mode with
-auto pager.  Requires Python (>= 2.5.0) and less.
+Term based tool to view colored, incremental diff in unified format or side by
+side with auto pager.  Requires Python (>= 2.5.0) and less.
 
-See demo at homepage: https://github.com/ymattw/cdiff
+AUTHOR  : Matthew Wang <mattwyl(@)gmail(.)com>
+LICENSE : BSD-3
+HOMEPAGE: https://github.com/ymattw/cdiff
 """
 
 import sys
 import difflib
 
 
+# REMEMBER UPDATE ``CHANGES``
+__version__ = '0.1'
+
+
 COLORS = {
     'reset'         : '\x1b[0m',
     'underline'     : '\x1b[4m',
 
     supported_vcs = [check[0] for check, _ in REVISION_CONTROL]
 
-    usage = '%s [options] [diff]' % os.path.basename(sys.argv[0])
+    usage = '%prog [options] [diff]'
     description= ('View colored, incremental diff in unified format or '
                   'side by side with auto pager.  Read diff from diff '
                   '(patch) file if given, or stdin if redirected, or '
                   'diff produced by revision tool if in a %s workspace') \
             % '/'.join(supported_vcs)
 
-    parser = optparse.OptionParser(usage=usage, description=description)
+    parser = optparse.OptionParser(usage=usage, description=description,
+            version='%%prog %s' % __version__)
     parser.add_option('-s', '--side-by-side', action='store_true',
             help=('show in side-by-side mode'))
     parser.add_option('-w', '--width', type='int', default=80, metavar='N',