Add caching of load saved pickled files for datasets.
Fix circular import
Don't cache what isn't under PYLEARN2_DATA_PATH.
Remove timming as now Theano is ~20x faster in that case (for the second call).
Update url to point to the right place.
Allow the buildbot to pass extra parameters
Add missing import
pep8 remove from white list some of the file I changed.
Implements missing FlattenerLayer functions.

Signed-off-by: Axel Davy <axel.davy@ens.fr>
Open a temporary file with writable mode in 'pylearn2/utils/image.py'.

Invocating 'file.flush()' for a file opened with read-only mode may
cause the EBADF (Bad file descriptor) error in some environments such
as Mac OS X 10.8.0.

Since the behavior seems to be undefined in the ISO C standard, the
temporary file should be opened with writable mode.

See:
  https://mail.python.org/pipermail/python-bugs-list/2002-June/012231.html
  http://www.opensource.apple.com/source/Libc/Libc-825.40.1/stdio/FreeBSD/fflush.c
Create a temporary file with 'tempfile.mkstemp()'.

To avoid the race condition on versions of Python prior to 2.7, a
temporary file is created by using 'tempfile.mkstemp()' instead of
'tempfile.NamedTemporaryFile()'.
Add a comment about NamedTemporaryFile() to 'pylearn2/utils/image.py'.
Merge pull request #873 from nouiz/mixed

cache more stuff and disable others.
Fixed bug in CompositeLayer class and added unit test for it
Merge pull request #919 from bartvm/composite_fix

Fixed bug in CompositeLayer class and added unit test for it
Merge pull request #918 from cvmat/fix_temporary_file

Fix temporary image file creation
Merge pull request #848 from axeldavy/FlattenerLayerComplete

Implements missing FlattenerLayer functions.
Merge branch 'master' of github.com:lisa-lab/pylearn2 into cv_validation_set