Optimize reading of changelists for recent p4d versions

Uses "p4 changes -r -m " which is beneficial when handling lots of changes
Requires a p4d r17.2 or greater version.

New YAML config file, and handle stream->stream transfers

This release has a new YAML config file, and auto-creates the transfer workspaces (source and target)
It also handles stream->stream transfers, with wildcards

Initial release of P4Transfer on Github

First release on Github - slightly refactored from the version in swarm.workshop.perforce.com (which will no longer be maintained).