Keep additional Boolean data for words

[dimztimz]

For each word we already keep a set of flags. We can keep additional data as a structure of Boolean variables where each Boolean variable represents the existence of special flags in the flag-set of the word. Code where the existence of special flags is queried can be replaced by checking a Boolean. This give us nice overall speedup for checking words. This internal feature should additionaly make easier to implement personal dictionaries.