ENH: support basinhopping solver in LikelihoodModel.fit()

- new _fit_mle_basinhopping()
- minimizer kwargs can be passed using 'minimizer' kwarg of dict type
base converged flag on res.message in _fit_mle_basinhopping()
use of score and hess arguments in _fit_mle_basinhopping()
update docstring of LikelihoodModel.fit()
TST: new TestProbitBasinhopping
add *args to _check_perfect_pred()
TST: remove no-op callback in TestProbitBasinhopping.setupClass()
Merge pull request #932 from rc/basinhopping

ENH: support basinhopping solver in LikelihoodModel.fit()
BUG fix lowess sort when nans closes #946
Merge pull request #949 from josef-pkt/fix_lowess_946

BUG fix lowess sort when nans closes #946
Another round of pyflakes/pylint cleanup. This commit covers the emplike and formula modules.
Fixed pyflakes in genmod: only one import error fixed due to overwrite in pull request 915.
Fix a docstring in KDEMultivariateConditional.
Merge pull request #956 from dougalsutherland/kde-doc

Fix a docstring in KDEMultivariateConditional.
Merge pull request #951 from guyrt/pylint-emplike-formula-genmod

Pylint emplike formula genmod
BUG/REF mcnemar fix exact pvalue, allow table as input
BUG: mcnemar restrict pval<=1 see #950
TST: runs, cochran_q move tests from module
TST cochran_q add another test from an example
TST cochran_q another test case from an example