fa.js: s/length > 0/length != 0/g.
fa.js: nfa_run_base - also accommodate single sid usage.
Introduce array_has().
fa.js: tom_nfa_matcher.can_transit() -> nfa_run_base.fa_can_transit().
fa.js: nfa_maker - use fa_eclose() instead of fa_ecloses() if suitable.
fa.js: move prepare_cur() into init(), respectively.
fa.js: introduce fa_phase_transit().
fa.js: cosmetics (?)
utils.js: remove unused dict_len().
fa.js: more cosmetics.
Add bt_nfa_matcher.