Merge branch 'release-v0.4.0' into develop
Add HEAD request support to fix #4
Change the Content-Type setter into the view

Only view knows Content-Type.
Fix refactor the code
Fix #5, 501 Not Implemented when no action code
Fix a bug that action definition is mixed
Fix error when loading fileless package
Change more readable in debug log
Fix that the preserve matched requires /p modifier
Fix to replace the bare keyword correctly
Remove environment parameter from config
Change the controller to not have app
Change app to have action instead of controller
Change to sort actions to prevent useless matching
Fix Smart::Comments enhancer

This commit has the following changes.

* Do not apply to all modules use warnings.
  By this behavior, it causes a problem in the module that
  contains `### [*NOT* Smart::Comments syntax]`.
  To enable Smart::Comments, use Slack::Util or use Slack qw(...)
* Add a version check before patching.
* Time::Piece one-liner can also be applied to a subclass.
* Fix the output encoding.
* Some fixes.
Add support for table output to Smart::Comments
Fix to ignore keyword when appears on hash key.
Change to have `prefix` instead of `appname`
Change to be able to define view of app
Change the required perl version

`use re qw(/flags)` requires re-0.14 or higher.