Creates a MIME::Type from an array in the form of:
          [type-name, [extensions], encoding, system]
        +extensions+, +encoding+, and +system+ are optional.
          Type.from_array("application/x-ruby", ['rb'], '8bit')
          # Type.from_array(["application/x-ruby", ['rb'], '8bit'])
        These are equivalent to:
          type = Type('application/x-ruby')
          type.extensions = ['rb']
          type.encoding = '8bit'

def from_array(cls, content_type,
                   extensions=[], encoding=None, system=None,
                   is_obsolete=False, docs=None, url=None, is_registered=False):
        """
        Creates a MIME::Type from an array in the form of:
          [type-name, [extensions], encoding, system]
        +extensions+, +encoding+, and +system+ are optional.
          Type.from_array("application/x-ruby", ['rb'], '8bit')
          # Type.from_array(["application/x-ruby", ['rb'], '8bit'])
        These are equivalent to:
          type = Type('application/x-ruby')
          type.extensions = ['rb']
          type.encoding = '8bit'
        """
        mt = cls(content_type)
        mt.extensions = extensions
        mt.encoding = encoding
        mt.system = system
        mt.is_obsolete = is_obsolete
        mt.docs = docs
        mt.url = url
        mt.registered = is_registered
        return mt