BUG: make sure GLM uses normal distribution, closes #828
TST genmod pylint, remove import *, remove some pylint noise (still some left)
MAINT: make Dataset pylint inspectable see #613
TST test_rlm.py cleanup so pylint can work (has no red) see #613
TST test_rlm, test for tvalues (benchmark), add normal distr checks closes #908
Merge pull request #909 from josef-pkt/bugs_misc_fixes9

Bugs in GLM pvalues, more tests, pylint