Fixed recursive directory removing on a Windows

RecursiveIterator variable should be destroyed to make rmdir
working instantly before we try to remove parentDir.
Fixes [UnexpectedValueException] during composer update command
on Windows system.
change wording for support hire a bit
add FAQ with "Should my module require the Installer"
Removed errors in code comment
Merge pull request #86 from vovayatsyuk/patch-1

Fixed recursive directory removing on Windows
add eloquent/composer-config-reader to requirements
Merge branch 'master' of github.com:magento-hackathon/magento-composer-installer into plugin-rewrite
a few changes to the Readme
add Thank You section to Readme