Decide on a cdr-log strategy for the CDRServer

[rostgaard]

For now. A pickup-script vacuums the log folder - which may be just what we want.
Otherwise, we will need to extend the CDRServer with a POST interface that renders the xml and puts it into the database.

[rostgaard]

For now. We just let FreeSWITCH store xml files and pick them up lazily.
This is safer, as we then get all the information from the PBX - rather than the information that we think we want.