fix bug in nfa_exec_step handling of NFAI_OP_MATCH_CLASS
add support for character classes in the example regex parser
add todo item (handle backslash escapes in regex parser)
add todo item (negated character classes in the regex parser)
fix bug in run.sh (incorrect quoting of arguments)
add support for (single character) escape sequences in the regex parser
update the todo list
make NFA_BUILDER_MAX_STACK and NFA_DEFAULT_PAGE_SIZE easier to change
extract the match loop from nfa_match to nfa_exec_match_string
update the manual to mention nfa_exec_match_string
update the readme
note in the manual the return value of nfa_exec_match_string