New Publishing / Scheduling implementation

Hi list,

today I committed some changes to the publishing and scheduling
process. Publishing is now done by a "publisher task" and an "exporter
task", you find some documentation about the task concept in the
developer's guide (section "Tasks").

The parameter names used by the publisher have changed from
docid/docids to sources/uris. I didn't yet adapt the menus of all
publications so that publishing and scheduling probably won't work in
most cases.

If you experience problems that could be related to this issue or
have any other questions, just contact me.

Andreas