php composer.phar install

composer.json

{
    "require": {
        "connect20/mage_all_latest": "1.7.*"
    },
    "repositories": [
        {
            "type": "composer",
            "url": "http://packages.firegento.com/"
        }
    ],
    "extra":{
        "magento-root-dir": "htdocs/",
        "magento-deploystrategy": "copy",
        "magento-force": true
    }
}