[FEATURE ] Add possibility to retrieve low-level Phar internals

[ohader]

Resolves: #9

Basic functionality

• reads Phar Stub content & extracts Phar::mapPhar usage (experimental)
• reads Phar Manifest as documented http://php.net/manual/en/phar.fileformat.manifestfile.php
• supports ZLIB & BZIP2 compression (.phar.gz, .phar.bz2)
• does NOT implement signature handling

Usage of Reader

$reader = new \TYPO3\PharStreamWrapper\Phar\Reader('storage/bundle.phar');
$container = $reader->resolveContainer();
// retrieves alias name, either from Stub (experimental) or from Manifest
$alias = $container->getAlias();
// retrieves meta-data array, fails in case it contains (malicious?) serialized objects
$metaDataArray = $container->getManifest()->deserializeMetaData();
// output
var_dump($container);

Possible output for $container

class TYPO3\PharStreamWrapper\Phar\Container#7 (2) {
  private $stub =>
  class TYPO3\PharStreamWrapper\Phar\Stub#8 (2) {
    private $content =>
    string(5) "<?php"
    private $mappedAlias =>
    string(0) ""
  }
  private $manifest =>
  class TYPO3\PharStreamWrapper\Phar\Manifest#9 (8) {
    private $manifestLength =>
    int(224)
    private $amountOfFiles =>
    int(3)
    private $apiVersion =>
    string(5) "1.1.0"
    private $flags =>
    int(65536)
    private $aliasLength =>
    int(9)
    private $alias =>
    string(9) "bndl.phar"
    private $metaDataLength =>
    int(35)
    private $metaData =>
    string(35) "a:1:{s:6:"vendor";s:9:"TYPO3Demo";}"
  }
}