[sync] Going forward with SyncML

[Anthony Mills]

I still need to finish the Sync sub command classes.  These classes should work
no matter how we do the rest of the SyncML server.  SyncML runs commands in
order and they always return a status.  The classes are not complete, but they
have enough information to do simple syncs.  I will finish the subcommands and
add the sync methods, then we will need to build the api.  What files should
the api reside in?  and how should we get the horde uids from the client uids? 
When I did it before I used a new table.

Thanks, Anthony