[sync] kronolith, turba, mnemo, nag external api

[Karsten Fourmont]

Hi,

the syncml module uses the external api in api.php of kronolith, turba, 
mnemo, and nag.

There are some issues with the api when it comes to horde sources 
(source= which notepad|tasklist|calendar to work on).

1) The listBy functions need an additional (optional) source parameter . 
Currently it returns data for all sources, whether the user can access 
them or not. that's plain wrong. If the parameter is not provided, the 
default source will be used. Like for import and export.

2) The list function currently returns all uids of all sources the user 
is allowed to see (or for nag: has set in GLOBALS['display_tasklists']). 
I'd like to add a source parameter here too and make the default to list 
only the data of the default source, rather than all sources. So all api 
functions have the same semantics: work on the default source unless a 
specific source is provided. If you really want data from all sources, 
you can still retrieve the list of all sources via the api.

Comments?

Cheers,
  Karsten