added composer setup and the first composer package php-archive

.gitignore

composer.json

composer.lock

inc/init.php

lib/plugins/extension/helper/extension.php

vendor/autoload.php

vendor/composer/ClassLoader.php

vendor/composer/autoload_classmap.php

vendor/composer/autoload_namespaces.php

vendor/composer/autoload_psr4.php

vendor/composer/autoload_real.php

vendor/composer/installed.json

vendor/splitbrain/php-archive/.gitignore

vendor/splitbrain/php-archive/.travis.yml

vendor/splitbrain/php-archive/LICENSE

vendor/splitbrain/php-archive/README.md

vendor/splitbrain/php-archive/composer.json

vendor/splitbrain/php-archive/phpunit.xml

vendor/splitbrain/php-archive/src/Archive.php

vendor/splitbrain/php-archive/src/FileInfo.php