Merge tag '0.19.0' into fork-0.19.0.0

Update date for release

Merge pull request pcapriotti#476 from pcapriotti/topic/0.18.1

Use layoutPretty instead of layoutSmart when rendering help texts.

Merge pull request pcapriotti#474 from pcapriotti/topic/0.18.0

Move to Pretty Printer Proper

Merge pull request pcapriotti#445 from pcapriotti/topic/version-0.17.0.0

Prepare version 0.17

Merge branch 'helper' into fork

Control special file/directory behavior in completions

Update cabal file and changelog

Use bash from $SHELL when it makes sense

Merge pull request pcapriotti#399 from pcapriotti/topic/0.16

Update changelog for release