(Bug 5329) clarify that only registered users can vote in polls
-- separate whoview and whovote security strings in en.dat
-- use new strings in poll.pm and /poll/create
-- move old strings to deadphrases.dat
-- also move old poll.security to deadphrases
Merge pull request #639 from ninetyd/bug5329/createpoll/textstrings

(Bug 5329) clarify that only registered users can vote in polls