[sync] MaxMsgSize, current status, first gui page

[Karsten Fourmont]

Hi,

I started work on the MaxMsgSize issue: devices like the Synthesis
client limit the size of SyncML messages (to s.th. like 10000bytes). If
a packet exeeds this size, it has to be split into two messages.

This itself is not too tricky to deal with, but our strange way of
handling commands (see http://wiki.horde.org/SyncRoadMap, Code Cleanup)
makes it harder then necessary: basicly atm a <sync> command can only be
sent in response to a <sync> by the client...

So a bit of refactoring is needed before I can tackle the actual
MaxMsgSize thing. I won't be able to do much work on it for the 
following week, so I've checked the current status in:

For the time being, the implementation honors the MaxMsgSize tag in the
following way: it puts sync element entries into the message until the
maxmsgsize is reached. Then it just stops. So when doing a slowsync,
maybe only the first 15 calendar entries are synced. You can manually
enforce "re-syncing" in later delta-syncs by manually editing and saving
the missing entries to update the "modified" timestamp of these entries.

That's not very helpful for production usage, but works for testing.

While at it, I checked in another thing that's not finished at all yet: 
a SyncML options page in the gui. However atm there are no options to 
configure. But to other things: first a list of successful sync 
timestamps: for each of those there's a button to delete the timestamp 
and so enforce a new slow sync on the next run. At the moment the 
client<->server ID map is not deleted by this, so the slowsync shouldn't 
produce too many duplicates.

The second thing on the gui page is a log of the previous sync session. 
Helpful for debugging.

To see the page you need to update your config/prefs.php from 
prefs.php.dist, logout and back in and then go the horde options.

This is work in progress, any suggestions for a final form of syncml gui 
(what to put where) are welcome.

Cheers,
  Karsten