(Bug 4532, 5142, 5143) Convert /feeds - remove raw.bml

This isn't serving a useful purpose, so remove it and redirect to /feeds/list.
(Bug 4532, 5142, 5143) Convert /feeds - new function LJ::Feed::synrow_select

Refactored repeated raw SQL statement from index.bml into new function
in LJ/Feed.pm for better maintainability.  Also fixed a warning
"uninitialized value in subtraction" in a different section of Feed.pm.
(Bug 4532, 5142, 5143) Convert /feeds - remove LJ::Syn module

Between LJ::Feed, LJ::Syn, and LJ::SynSuck, I really felt like we had
too many code modules related to feed management, so I merged LJ::Syn
into LJ::Feed.
(Bug 4532, 5142, 5143) Convert /feeds - move BML files to DW::Controller::Feeds

Three new templates: /feeds/index, /feeds/list, and (interstitial) /feeds/name
(Bug 4532, 5142, 5143) Convert /feeds - tweaks as requested

Separated get args and post args, used automatic form_auth check,
fixed whitespace, etc.

Made one extra tweak to name.tt, removing an unneeded paragraph tag.
(Bug 4532, 5142, 5143) Convert /feeds - use default subscription filter

Found a small bug in testing where if you added a feed from the list of
checkboxes, the feed wouldn't get added to the user's default filter.
All the other paths redirect to the subscription management page.
Merge pull request #529 from kareila/bug2077-feeds

(Bug 2077) convert /feeds BML pages to TT