removed useless exception declaration

Signed-off-by: Alessandro Bahgat <ale.bahgat@gmail.com>
Refactored avaiable in available

Signed-off-by: Alessandro Bahgat <ale.bahgat@gmail.com>
added NoSuchAlgorithmException to Metafile constructor

Signed-off-by: Alessandro Bahgat <ale.bahgat@gmail.com>
Added a basic .gitignore