fixed prints for python3 support

[maciejstromich]

in Python 3.X print is a function and it has to have parentheses.

Installing the module from pip in python3.4 shows

ownloading/unpacking httpheader
  Downloading httpheader-1.1.tar.gz
  Running setup.py (path:/Users/suff/projects/hht/venv/build/httpheader/setup.py) egg_info for package httpheader

Installing collected packages: httpheader
  Running setup.py install for httpheader
      File "/Users/suff/projects/hht/venv/lib/python3.4/site-packages/httpheader.py", line 499
        print 'Comment test failed:'
                                   ^
    SyntaxError: Missing parentheses in call to 'print'


Successfully installed httpheader

and after the changes:

Unpacking /Users/suff/projects/httpheader
  Running setup.py (path:/var/folders/py/q29w3rl5641gm8tkkbdw7_l00000gn/T/pip-7bnqiam5-build/setup.py) egg_info for package from file:///Users/suff/projects/httpheader

Installing collected packages: httpheader
  Running setup.py install for httpheader

Successfully installed httpheader
Cleaning up...

[jbrockmendel]

+1