Merge branch 'release/0.04'
Fix for #270, serializer options were being ignored
 fix for issue #274 and dancer2 -v now returns the right version
Don't use rootdir for app location

The app location directory code recurses upwards looking for
a directory with 'bin' or 'lib' or '.dancer'.

This commit prevents it from reaching the root directory.
Make file logger flock when writing
Clean up File logger config and documentation
HEAD request drops the body of the response.

For a HEAD request, the body of the response should be empty ('').  By
implementing an 'around' modifier to the 'dispath' method, we can drop
the body if the request is HEAD.

The reason to use an 'around' modifier in this case, is that the
Content-Length head should contains the correct lenght of the response.

Closes #286.
Drop response's body when the status is 1x or [23]04.

The body should be empty ('') when the status is set to 1xx or when
it's 204 (No Content) or 304 (Not Modified).
Fix for the default tests of a new generatd app.

The tests of an app generated by the `dancer2` scripts are failing
because the tests can't load the application.

By specifiying the name of the application to load in the test we can
make them pass.

Also, in the Dancer2::Test module, before calling the 'can' method on
the caller, we check if the caller is defined, that way, instead of
failing the tests because we can't call a method on an undefined object,
we fail with a useful message for the user.

Closes #293
Check 'show_errors' when returning an internal error.

When returning an internal error, exceptions should not be returned in
the response if the value of 'show_errors' is set to false in the
configuration.

In order to do this, instead of passing the message and the exception as
a single value to Dancer2::Core::Error, we separate them and use the
correct attribute when creating the object.

When the method `throw` is called, the value of 'show_errors' is
checked, and if it's false, the exception is not used in the message.

Tests are updated accordingly to this change.

Closes #216
Merge pull request #297 from franckcuny/pr/check-show_errors

Check 'show_errors' when returning an internal error.
Merge pull request #296 from franckcuny/pr/fix-defaults-tests-app

Fix for the default tests of a new generatd app.
Merge pull request #295 from franckcuny/pr/drop-content

Drop response's body
Merge pull request #294 from franckcuny/pr/head-drop-body

HEAD request drops the body of the response.
Merge pull request #289 from dagolden/feature/flock-file-logger

Improve File logger
Merge pull request #287 from dagolden/feature/no-root-location

Don't use rootdir for app location
Merge pull request #277 from drebolo/devel

 fix for issue #274 and dancer2 -v now returns the right version
Merge pull request #273 from keithbro/devel

Fix for #270, serializer options were being ignored