Update ExtractTask.php

Correct plugin Locale path: inside src folder (plugins/_NAME_/src/Locale, not plugins/_NAME_/Locale)
Update FormHelper.php

An pull request for #4410.
Update ExtractTask.php

Fix with Plugin::classPath as @markstory suggested
Validating mimetypes now require ext/fileinfo

Validating files must be done carefully, and File::mime() is too helpful
to be realiable. This also removes the dependency from Validation to
Filesystem
Removing the magic localized validation in the Validation class

This can be done much nicer and cleaner using validation providers
with the Validator class.
Removing whitespace
Merge remote-tracking branch 'origin/3.0' into 3.0-cleaner-validation

Conflicts:
	src/Validation/Validation.php
Merge branch '3.0-cleaner-validation' of github.com:cakephp/cakephp into 3.0-cleaner-validation
Allow setting default route class.
Allow setting default route class for RouteBuilder.
Pass default route class as an option to RouteBuilder constructor.
Merge pull request #4453 from cakephp/3.0-route-class

3.0 default route class
Merge pull request #4407 from luke83/patch-3

Update ExtractTask.php
Add Inflector::hyphenate().
Return null instead of false on cache miss.

Null better represents "no value found".
Fix ViewTask generating links for self associations.

When getting the list of associations, self associations should be
excluded.

Refs #4440
Fix fixture generation.

When generating fixtures don't add fixtures for self associated models.
Generally all instances of one class will use the same fixture and
including additional fixtures for aliases will only cause problems.

Refs #4440
Update "static" keyword instead of class name.
Improve arugement name and docblock.
Add tests for null and false input to inflector methods.