[jonah] updates to jonah

[Marko Djukic]

i have a quite a few updates to jonah lined up that i'll try to commit shortly.
there are some important improvements, briefly:
- i've started splitting jonah up into separate classes/objects for
news/weather/stocks etc. for now news is the one which is nearing completion.
- news now has a single backend object which handles both external and
internally authored channels. /jonah/config/channels.php is no longer needed,
everything is stored in the backend.
- for now i have a sql backend done (what could be other backend types?)
- i've done quite a bit of renaming to get the terminology standardised (ie.
minor things like a channel is now always a "channel", no longer a "source").
- caching of news items is now done using Horde_Cache, eliminating the need for
/var/jonah directories.
- cache/udpate interval for external channels can now be set into the backend
and with the use of Horde_Cache all updates are handled in the background
without user intervention or the need for CLI access/scripts.
- only Horde Admin has access to the setup of channels into the backend AND the
authoring of internal channels.
- the /jonah directory started getting crowded with the scripts so i tucked away
admin scripts into respective /jonah/news, /jonah/weather, etc... directories.
any objections to this? the non-admin type scripts (newsfeed etc) i am leaving
in the root /jonah directory.

the implications following all of this:
- any channels listed in the /config/channels.php file will need to be moved to
the backend (any offers for a quick script to do this? i'll try and get to it
myself otherwise)
- any channels will have to be resubscribed, because their channel_ids have
changed
- any channels set up using Horde_Blocks (portal.php etc) will need to be
reinserted, again because of all the channel_id changes.

this is still a biggish work-in-progress - a lot of conf.php options to allow
fine-tuning of jonah's behaviour are still missing and there are still a few
rough edges news... i should get those sorted out very soon, followed by some
updates to other parts of jonah (weather etc).

marko