Boggle Solver
Call Boggle(size, layout, wordlist) to generate board. size is a tuple of
columns and rows on the board (default 4x4). 'layout' is a row major array of
strings to map to board; if not set layout is randomly generated. wordlist
is wordlist is a string of valid words, or a path to a text file with valid
words. Call the findWords() method to search the board.