- Create VCP::ConfigFileUtils and move bin/vcp::parse_config_file
in to it.
- Add VCP::ConfigFileUtils::write_config_file()
- Add --output-vcp-file to bin/vcp.
- Add VCP::Driver::repo_spec_as_string()
- Add VCP::Driver::config_file_section_as_string()
- VCP::Driver::parse_repo_spec() now clears any settings that
are not set by a given spec string (so old values don't
remain after a call to it).