module Kramdown::Options

names are considered and their value is run through the #parse method.
Merge the #defaults Hash with the *parsed* options from the given Hash, i.e. only valid option

def self.merge(hash)
  temp = defaults
  hash.each do |k,v|
    k = k.to_sym
    next unless @options.has_key?(k)
    temp[k] = parse(k, v)
  end
  temp
end