ENH: use lgamma function from John D. Cook

Conflicts:
	sklearn/metrics/cluster/expected_mutual_info_fast.c
	sklearn/utils/lgamma.cpp
	sklearn/utils/lgamma.pyx
	sklearn/utils/setup.py
Merge branch 'master' into lgamma_port

Conflicts:
	sklearn/metrics/cluster/expected_mutual_info_fast.pyx
Merge pull request #24 from glouppe/adaboost

Fix some nitpicks
EXAMPLE don't use deprecated interface in lasso model selection
COSMIT pep8 in examples
COSMIT pep8
DOC more sphinx fixes
FIX sort indices in CSR matrix for SVM
DOC fix travis URLs in README

https://secure.travis-ci.org/scikit-learn/scikit-learn incorrectly
redirects to https://travis-ci.org//scikit-learn/scikit-learn, which
doesn't work.
TST sorting CSR matrix indices in SVMlight file handling
dpgmm: setting the weights to something reasonable
TST add regression tests for Alex' fix.
COSMIT: pep8
ENH rename cosine_kernel to cosine_similarity. Also make the test actually do something.
DOC improve cosine similarity docs
TEST: fixing randomly failing test

On my box this test would fail for errors on the order of 1e-15
DOC fixed problem in citations in spectral_embedding
COSMIT typos
ENH don't use deprecated class_prior fit parameter for NB in test
ENH in spectral_embedding: do input validation before anything else