Merge tag '3.9.0' into develop

3.9.0
Test inline comments for `import as` statements
Don't strip comments from `import as` lines
Don't set combine_as_imports in test cases.
Merge pull request #179 from dandavison/dont-strip-as-comments

Dont strip `as` comments
Merge pull request #180 from dandavison/dont_combine_as_imports_by_default_in_tests

Don't set `combine_as_imports` in comment test cases.
Add Dan Davison (@dandavison) to acknowledgements for his work improving as comment output
Added show_diff to config
Merge pull request #187 from FalconSocial/add-show_diff-to-settings

Added show_diff to config
Added possibility to run with options 'show diff' and 'check' together
fixed typo
Add config for known future library imports.

This allows them to be grouped with __future__ imports.
Merge pull request #191 from QuLogic/known-future-imports

Add config for known future library imports.
Merge pull request #190 from MaciejWo/diff_and_check

Added possibility to run with options 'show diff' and 'check' together
Expand akcnowledgements to include most recent contributers @dinoshauer, @qulogic, and @maciejwo
Add failing test, while I work on a fix
Fix isort behaviour with comment on multiline import
Fix for issue #192 complete
Merge pull request #193 from timothycrosley/feature/fix-issue-192

Feature/fix issue 192
Add test for issue #182