Keyword class
Encapsulates a keyword ("foo is bar" is a keyword called foo, with type is, and has a single value of bar). Keywords can have multiple values, to_s() will choose one at random
escape special words/characters in a keyword
create a keyword of type type with values values
deserialize the stringified form to an object
unescape special words/characters in a keyword
add values to a keyword
describe the keyword (show all values without interpolation)
return the keyword in a stringified form ready for storage
pick a random value for this keyword and return it
[Validate]