Update controller task to use magic get.

Now that association objects can be accessed using `__get()` bake can
have shorter syntax in the generated actions.
they should _not_ declare a config property
Fix errors reading postgres timestamp columns.

Timestamp columns from postgres often include the milliseconds. Since
that data cannot be stored in DateTime instances, we should chop it off.

Fixes #3087
Merge pull request #3119 from cakephp/controller-bake-update

Update controller task to use magic get.
determine read/write from the number of func arguments

rather than whether the value is null. Prevents problems with for
example:

	$inst->config('setthis', 'some value'); // or the default
	...
    $something = $couldBeNull;
	$inst->config('setthis', $something);

which would be pretty confusing.

Also add the possibility to delete a config key - same use case/example
as above
phpcs fixes

and add a test for when deleting should fail
Merge pull request #3116 from AD7six/3.0-config-core

add an instance config trait
update Controller NS to be settings -> config()

Ref #2298
make use of the instance config trait
nolonger used