Make Registry support recursive bindData

This is just a little recommend of make Registry recursive merge a new loading file.

### Before

``` php
$json1 = '{
    "field" : {
        "keyA" : "valueA",
        "keyB" : "valueB"
    }
}';

$json2 = '{
    "field" : {
        "keyB" : "a new valueB"
    }
}';

$registry->loadString($json1);
$registry->loadString($json2);
```

Output

```
Array(
    field => Array(
        keyB => a new valueB
    )
)
```

### After

``` php
$json1 = '{
    "field" : {
        "keyA" : "valueA",
        "keyB" : "valueB"
    }
}';

$json2 = '{
    "field" : {
        "keyB" : "a new valueB"
    }
}';

$registry->loadString($json1);
$registry->loadString($json2);
```

Output

```
Array(
    field => Array(
        keyA => valueA
        keyB => a new valueB
    )
)
```
Using single if instead ternary operation in Registry::bindData()
Using bindData() in Registry::merge()

Thanks @dongilbert
Add chaining to load*() methods and add recursive params to merge & bindData
Update Registry Manual
Rewrite RegistryTest for recursive merge
Add convention for naming variables
Adding comments in the examples of variable convention naming
Remove not needed `
Merge pull request #220 from asika32764/patch-2

Make Registry support recursive bindData
Merge pull request #235 from javigomez/staging

Adding naming convention for variables
Change Factory::getStream to Stream::getStream
Fix failing unit test
Merge pull request #236 from dongilbert/bugfix-FilesystemJFactoryGetStream

Remove JFactory::getStream from the Filesystem Package
Replace Mysql Driver with PDO version
Merge pull request #218 from asika32764/pdomysql

Replace MySQL driver with PDO version #82
joomla-framework: Implemented Redis Cache Handler
joomla-framework: Redis Cache Handler - small corrections
joomla-framework: Redis Cache Handler - fix for improper checking for returned value in Cache\Redis::get()
extended test cases
joomla-framework: Redis Cache Handler - additional test cases
for setting, getting and removing multiple items