renamed handlers for consistency

cf. 8b15842fb8b993a79f8ebdb093eb1642c8ebc210
fixed typo
improved portability

apparently BSD ln is less clever - which might be a good thing
fixed failing test

this was due to an erroneous change in
8b15842fb8b993a79f8ebdb093eb1642c8ebc210: the `wiki_index` handler's
aborts, redirecting to challenger, before it can redirect from /alpha to
/alpha/index