select all text upon clicking passphrase
select all text upon clicking passphrase

that way the example will show and will clear upon typing
also removed some, but not all redundant/repeated getElementById calls
to a new onLoaded function.

QUINTIX/PassphraseHasher,QUINTIX/HTML-Passphrase-Hasher,QUINTIX/PassphraseHasher,QUINTIX/PassphraseHasher,QUINTIX/HTML-Passphrase-Hasher