add _add + friends feed to api

[sysadminmike]

_add
_enable
_disable
_remove
All need to accept json as get/post request and keep it couchy

_feeds_status - list all feeds - current /_status does this - add more info about feed
_status - change to give status about daemon + postgres connection + watchdog + pg_watchdog and any other global info

[sysadminmike]

_restart_feed - needs feed name
_kill_feed - needs feed name set feed alive to false - watchdog will then sort it out
_restart
_set_initial-since - ie UPDATE since_checkpoints table SET since = ?
_set_current_since - update changecount var in daemon and restart stream
_set_stream_checkpoint_interval - allow different intervals per stream - so if couch local increase but if remote on bad connection decrease it - or if very noisy db then increase
_set_pg_watchdog_interval - how often we check posgres alive
_set_watchdog_interval - how often we check to kill/reap stalled/dead feeds
_set_finder_interval - how often do we check since_checkpoints table for new feeds or enabled/disable change
_kill_pg - kill postgres connection - ie set postgres_dead = true

need get* for most of the above to - or maybe easier to add _status json output

i think thats most of the knobs anyone would need to adjust in the daemon may have forgotten one or two

I think with node it possible to change the http server port without or even connection postgres setting restarting the daemon - not sure how useful that is though - maybe changing postgres settings in high availability scenarios but with couch and this it would be safer to just setup a new server and node daemon.