Php app db support

Remote support was added for php applications. Older versions work only in localhost.

Database configuration parameters were added to YAML. Below, we can see a php deployment example using a git repo and how the given parameters for configuring a database connection.

``` yaml
- serviceType: brooklyn.entity.webapp.apache.ApacheServer
  name: Apache Server
  location: aws-ec2:us-west-2
  brooklyn.config:
    http_port: 80
    app_git_repo_url: https://seaclDem:seaclouds@bitbucket.org/seaclDem/nurocasestudyphp5-5.git    
    db_connection_file_config: config/config.php
    db_connection_config_params:
      g_DatabaseHost: $brooklyn:formatString("%s", component("db").attributeWhenReady("host.address"))
      g_DatabasePort: $brooklyn:component("db").attributeWhenReady("mysql.port")
      g_DatabasePassword: br00k11n
      g_DatabaseUser: brooklyn
```

The parameter ```db_connection_file_config``` specifies the configuration file inside php application which contains the necessary parameters to establish the connection with the database. 
This file should be contains a sentence like the next one for each necessary parameter:

```php
define( %parameterID, %value);
```
Below, we can see a list of parameters definition for a database connection. In this case, we have given a default configuration using general values. As soon as the parameters contains expected values by the database, the connection will be establish.
``` php
define( 'g_DatabaseHost', '127.0.0.1'); #database host ip
define( 'g_DatabasePort', '3306'); #port
define( 'g_DatabaseName', 'database1'); #name of the database
define( 'g_DatabaseUser', 'seaclouds'); #allowed user for the database
define( 'g_DatabasePassword', 'seaklouds'); #database password
```
However,  this values could depend of the runtime values, e.g. the  database host ip could be known when the database host is deployed. So, the configuration by default it is not always correct.

The required parameters showed before are configured using  ```db_connection_config_params```. It is a map what define the values for each parameter defined in the file pointed by ```db_connection_file_config```. Then the above yaml example will modify the ```config/config.php``` in the next way:

```php
define( 'g_DatabaseHost', %depend-of-the-database-host); #database host ip
define( 'g_DatabasePort', %depend-of-the-database-server); #port
define( 'g_DatabaseName', 'database1'); #name of the database
define( 'g_DatabaseUser', 'seaclouds'); #allowed user for the database
define( 'g_DatabasePassword', 'seaklouds'); #database password
```

The php application should understand these parameters for connecting with the database.