Fixed script run_tests_in_batch so that it works even when the 'nosetests' command cannot be directly called from subprocess.

This happens for instance on Windows when nosetests was installed within MinGW with "python setup.py install".

The problem was that numpy added new data types, like complex192 or float96,
that are currently not supported by Theano. The tests would try to test Theano
behavior on these new datatypes.

Also in this commit: removed a warning in tests when config.int_division is set to 'int'.

Also removed a part of a warning that is not needed anymore, since the line
triggering the warning should now be displayed.

Fixed C compilation crash under Windows 32 bit, where setting a theano_complex64 to 0 was not supported

- Partially removed a confusing mention of THEANO_FLAGS which was a leftover
  from a previous version where it was shown in the suggested nosetests command
- Removed mention of warn.ignore_bug_before since tests are now automatically
  configured to avoid printing those warnings

This is needed e.g. for the --with-id option of nosetests to work properly.

merge w conflicts in cuda init and nvcc_compiler - I had to clobber my previous commits which were bad

This is useful e.g. to be able to copy a precompiled cutils_ext into the
compiledir *after* reading the value of theano.config.compiledir.

- Fixed crashes in an unusual Python 2.4.4 Windows environment when calling
  subprocess.Popen with a mix of PIPE and None values for stdout, stderr and
  stdin.

- Fixed crashes when using a C cache copied from another location.