BUG pandas 0.15 compatibility in grouputils labels
Merge pull request #1886 from josef-pkt/BUG_grouputils_pandas_compat

BUG pandas 0.15 compatibility in grouputils labels
ENH: add tools.testing module for asserts (numpy, pandas compat wrapper)
TST: pandas compat: change asserts (failing with pandas master for 0.15)
TST test_corrpsd Test_Factor: add noise to data
Merge pull request #1888 from josef-pkt/corr_nearest_factor_1850_4

TST test_corrpsd Test_Factor: add noise to data
Merge pull request #1887 from josef-pkt/BUG_pandas_compat_asserts

ENH/TST: pandas compat asserts, new statsmodels.tools.testing
BUG: fix ytick positions closes #1561
Merge pull request #1889 from josef-pkt/BUG_multicomp_plot_1561

BUG: fix ytick positions closes #1561
BUG: MultiComparison use array for groups closes #1890
BUG fix more ix indexing cases for pandas compat closes #1891
TST: add tukeyhsd/MultiComparison test with pandas.Series
Merge pull request #1894 from josef-pkt/BUG_pandas_compat_ix

BUG fix more ix indexing cases for pandas compat
BUG: work with bytes, use dtype object in pandas.Series
Merge pull request #1895 from josef-pkt/BUG_multicomp_pandas_1890

Bug multicomp pandas asarray
TST: fix assert_equal for pandas index, (was left out of PR #1887)
Merge pull request #1899 from josef-pkt/pandas_compat_assert

TST: fix assert_equal for pandas index
BUG: LikelihoodModelResults.conf_int use df_resid_inference closes #1903
Merge pull request #1914 from josef-pkt/bug_pvalues_use_t_1903

BUG: LikelihoodModelResults.pvalues use df_resid_inference
Add option to set covariance clipping method, improve reporting of linalg errors