spamassassin: whitespace cleanups

removed lots of trailing whitespace
spamassassin: added spamassassin.ini
store spamd response in connection note,

added per-user SA pref support for vpopmail
refactored into paragraph sized functions
SA docs: fix typo & grammar error
spamassassin: pass SA headers through unaltered

this allows sites to customize the presence and appearance of SA headers without touching this plugin
spamassassin: use parseFloat for numberic compare