Validate tarball and installed files
add validate-lint.sh

and factor some common stuff into validate-common.sh, plus don't ship
these validation scripts in sdist tarballs.
update travis to run validation
fix W391
fix E302
fix E301
fix E261
fix E225
Fix E711
E712, E721, E122, E123, E211 weren't a problem
fix E126
E128 wasn't a problem
fix E501
require pep8 for tests
add pylint
coalesce validation into a single script
run in bash