* the dictionary loader now supports word frequencies
* word frequency validation upon building
* added default word frequencies to all dictionaries
* updated documentation
* added missing words to the Bulgarian dictionary
* English dictionary update
* removed repeating words from the Italian and Bulgarian dictionaries
* fixed incorrectly broken words and removed repeating ones from the Ukrainian dictionary
* Russian dictionary update
* documentation update
* made it possible to type words with apostrophes (Dutch, English and Ukrainian)