Fixed exception caused by printing CUDA program object

[ringw]

Hi, I found the following issue when using the CUDA API:

>>> import reikna.cluda
>>> api = reikna.cluda.cuda_api()
>>> thr = api.Thread.create()
>>> prg = thr.compile('')
>>> print prg
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "reikna/cluda/api.py", line 452, in __getattr__
    return self._thr.api.Kernel(self._thr, self._program, name, static=self._static)
  File "reikna/cluda/api.py", line 469, in __init__
    self._static = static
  File "reikna/cluda/cuda.py", line 208, in _get_kernel
    return program.get_function(name)
  File ".../pycuda/compiler.py", line 275, in get_function
    return self.module.get_function(name)
pycuda._driver.LogicError: cuModuleGetFunction failed: not found

It looks like print tries to use prg.__repr__, so prg looks for a function called "__repr__". I changed reikna.cluda.api.Program to inherit from object so it behaves as a "new-style class", which apparently causes it to use the default __repr__ implementation instead of calling prg.__getattr__("__repr__").

[fjarri]

Thanks!