Merge remote-tracking branch 'upstream/master' into enh/metrics

* upstream/master: (823 commits)
  Set the download link to PYPI.
  Address Issue #590 : use relative path link to about.html
  check random state in _fit_transform
  add random_state to LocallyLinearEmbedding
  MISC: fix bibtex
  Add n_jobs option to pairwise_distances and pairwise_kernels.
  euclidian_distances is to be deprecated in v0.11.
  Better default threshold for L1-regularized models.
  Remove CoefSelectTransformerMixin and use SelectorMixin instead.
  COSMIT removed unused imports
  Cosmit: remove unused imports
  Refactor in KFold.
  COSMIT pep8
  FIX: MurmurHash3 compilation on older GCC
  DOC added required versions of python, numpy and scipy to install documentation. Closes issue #579
  DOC website: added link to 0.10 docs under support.
  FIX: broken build / tests
  Move preprocessing.py to sklearn/.
  preprocessing/__init__.py -> preprocessing/preprocessing.py
  ENH: Default in Vectorizer "None" as @ogrisel suggested
  ...