File format conversion and metadata discovery for Cheshire3.

All classes defined in this sub-package conform to the Cheshire3 object model 
and API. Noteworthy classes defined by this sub-package:

* DependentCmdLinePreParser:	
    Command Line PreParser to start an external service before processing document.

    
* CmdLineMetadataDiscoveryPreParser:
    Command Line PreParser to use external program for metadata discovery.
   
        
* XmlParsingCmdLineMetadataDiscoveryPreParser:
    Command Line PreParser to take the results of an external program given in XML, parse it, and extract metadata into a hash.
