Merge branch 'master' into psgi

Merge branch 'master' into psgi

master:
Version 5.80030
Fix a warning with undef bodies
Changelog the Package::Stash bugfix
Changelog the resp->body improvements
Work with PP Package::Stash again now the incorrect assumption that broke with ::XS is fixed
Stop relying on Package::Stash PP bugs
Add conflict
Bad test failed to show bug.
Fix the case for body '0'
Make response body able to be undef to allow RenderView to see 'defined but empty' body, allowing X-Sendfile to work nicer. Also removes horrible modifier code. win/win if it doesn't break anything else.
Extra links in docs
Add test case for uri_for() with #fragment and query params, broken by 5.7008 when uri_for() was reimplemented without URI.pm.
Found a another fault in chained action dispatcher.

Conflicts:
lib/Catalyst/Engine/CGI.pm