Adding a README and composer.json for the Datasource namespace

This is needed for extracting the ORM to its own package

composer.json

@@ -46,6 +46,7 @@
		"cakephp/event": "self.version",
		"cakephp/validation": "self.version",
		"cakephp/utility": "self.version",
		"cakephp/core": "self.version"
		"cakephp/core": "self.version",
		"cakephp/datasource": "self.version"
	}
}

src/Datasource/README.md

@@ -0,0 +1,77 @@
# CakePHP Datasource Library

This library contains interfaces for implementing Repositories and Entities using any data source,
a class for managing connections to any datasource and traits to help you implement quickly the
interfaces provided by this package.

## Repositories

A repository is a class capable of interfacing with a data source by using operations such as
`find`, `save` and  `delete` by using intermediate query objects for expressing commands to
the data store and returning Entities as the single result unit of such system.

In the case of a Relational database, a Repository would be a `Table`, which can be return single
or multiple `Entity` objects by using a `Query`.

This library exposes the following interfaces for creating a system that implements the
repository pattern and is compatible with the CakePHP framework:

* `RepositoryIntercace` - Describes the methods for a base repository class.
* `EntityInterface` - Describes the methods for a single result object.
* `ResultSetInterface` - Represents the idea of a collection of Entities as a result of a query.

Additionally, this package provides a few traits and classes you can use in your own implementations:

* `EntityTrait` - Contains the default implementation for the `EntityInterface`.
* `QueryTrait` - Exposes the methos for creating a query object capable of returning decoratable collections.
* `ResultSetDecorator` - Decorates any traversable object so it complies with `ResultSetInterface`.


## Connections

This library also contains a couple utility classes meant to create and manage connection objects. Connections
are typically used in repositories for interfacing with the actual data source system.

The `ConnectionManager` class acts as a registry to access database connections your application has. It provides
a place that other objects can get references to existing connections. Creating connections with the `ConnectionManager`
is easy:

```php
use Cake\Datasource\ConnectionManager;

ConnectionManager::config('master', [
    'className' => 'MyApp\Connections\CustomConnection',
	'param1' => 'value',
	'param2' => 'another value'
]);

ConnectionManager::config('slave', [
    'className' => 'MyApp\Connections\CustomConnection',
	'param1' => 'different value',
	'param2' => 'another value'
]);
```

When requested, the `ConnectionManager` will instantiate `MyApp\Connections\CustomConnection` by passing
`param1` and `param2` inside an array as the first argument of the constructor.

Once configured connections can be fetched using `ConnectionManager::get()`. This method will
construct and load a connection if it has not been built before, or return the existing known connection:

```php
use Cake\Datasource\ConnectionManager;
$conn = ConnectionManager::get('master');
```

It is also possible to store connection objects by passing the instance directly to the manager:

```php
use Cake\Datasource\ConnectionManager;
$conn = ConnectionManager::config('other', $connectionInstance);
```

## Documentation

Please make sure you check the [official API documentation](http://api.cakephp.org/3.0/namespace-Cake.Datasource.html)

src/Datasource/composer.json

@@ -0,0 +1,25 @@
{
	"name": "cakephp/datasource",
	"description": "Provides connection managing and traits for Entities and Queries that can be reused for different datastores",
	"license": "MIT",
	"authors": [
		{
			"name": "CakePHP Community",
			"homepage": "http://cakephp.org"
		}
	],
	"require": {
		"cakephp/core": "dev-master"
	},
	"suggest": {
		"cakephp/utility": "Require this if you decide to use EntityTrait",
		"cakephp/validation": "Require this if you decide to use EntityTrait",
		"cakephp/collection": "Require this if you decide to use ResultSetInterface",
	},
	"autoload": {
		"psr-4": {
			"Cake\\Datasource\\": "."
		}
	},
	"minimum-stability": "beta"
}