Implementation of pbraw export

Implementation of export of data to pbraw format, using the structure of the SLAC Archiver Appliance.
Ah, this needs to be configurable as it is a reflection of a site's PV naming convention.  For example, we use "[:-{}]".

Also, I don't like the idea of generating SQL statements conditionally (in two lists).  What happens if they seperation is wrong?  How about one list with 'insert if not exist', so that existing entries aren't overwritten.

Alternately, Is there some way this could be handled through the Appliance management API?  This looks like a case for "/putPVTypeInfo?..." (http://epicsarchiverap.sourceforge.net/api/mgmt_scriptables.html).

I'll ask Murali to comment on what the process would be to add the configuration for a PV which no longer exists.