Added P4DepotFile, P4Revision and P4Integration classes to
provide an easy to use way of examining responses from the server.
Currently used only by P4#run_filelog (see below). To be enhanced
in future versions.
Added P4#run_filelog definition. Previously handled by method
missing, now when used in tagged mode, the complex filelog
response is returned as an array of P4DepotFile objects. Each
P4DepotFile object has an array of P4Revision objects and each
revision has an array of P4Integration objects. This structure
makes it much easier to analyse the filelog data in a script.