metadata: replace semantic-version with a custom parser
    
    The library semantic-version changed a lot during the last versions,
    making the Metadata class very fragile.
    
    A custom-made semantic version parsed, based on some Cargo specifics,
    has been implemented to replace the old parser.
    
    As a result of that, new features were implemented, like the support for
    wildcard expressions, as documented in the Cargo book.
    
    Fix: #93