Clean up formatting, rework run wrapper script to not use globals.

tools/cov.py

 #!/usr/bin/python
 # Copyright 2014 Google Inc. All rights reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #    http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
@@ skipping 43 matching lines @@
     parser.add_argument('--source', action='append', default=[],
                         help='Limit coverage data to the given directories.')
 
     parser.formatter_class = argparse.RawTextHelpFormatter
     parser.epilog = textwrap.dedent("""
     Valid pragma values are:
         'no cover': The default coverage pragma, this now means we
                     truly cannot cover it.
         'no win32': Code that only executes when not on Windows.
         'python2':  Code that only executes under Python2.
-        'python3':  Code that only executees under Python3.
+        'python3':  Code that only executes under Python3.
         'untested': Code that does not yet have tests.
         'win32':    Code that only executes on Windows.
 
     In typ, we aim for 'no cover' to only apply to code that executes only
     when coverage is not available (and hence can never be counted). Most
     code, if annotated at all, should be 'untested', and we should strive
     for 'untested' to not be used, either.
     """)
 
 
@@ skipping 58 matching lines @@
     except SystemExit as e:
         ret = e.code
     cov.stop()
     cov.save()
     cov.report(show_missing=args.show_missing)
     return ret
 
 
 if __name__ == '__main__':
     sys.exit(main())