Update exceptions used in cache engines.
Fix tests.
Update exception in log classes.
Add Table::defaultValues()

This makes it easy to get the default values from a schema table. Having
this is really useful when you want to make an entity with the default
values from the database.

Refs #4398
Removing leading backlash in namespace use statement.
Update exception type.
Moving File and Folder to their own namespace
Fix default values in postgres.

Postgres returns additional data that is not helpful when building
entities or rebuilding schema.

Refs #4398
Unify irregular rules and simply code.
Add missing use statement.
Merge pull request #4448 from cakephp/schema-default

Add a simpler way to get column values
Merge pull request #4450 from cakephp/3.0-inflector

Unify irregular rules and simply code.
Merge pull request #4437 from cakephp/3.0-exceptions

Update exceptions used in cache engines.
Merge pull request #4447 from cakephp/3.0-filesystem

3.0 - Moving File and Folder to their own namespace
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