Synchronise RiMarkov/RiLexicon with java

[dhowe]

• [x] make sure options are clear (and clearly documented, see below)
• [x] attempt to create failing cases with new options set (ritajs)
• [x] sync java with new js code and tests in RiMarkov
• [x] sync java with new js code and tests in RiLexicon
• [x] check for other 'SYNC:' markers in js for upcoming release
• [x] Add 'text' option to RiTa.markov in docs if not there:

RiTa.markov(3, { text: stringOrArrayForModel });

[dhowe]

@Real-John-Cheung status on this?

[Real-John-Cheung]

should be finished now

[dhowe]

great, let me know if there were any issues or questions..