Use tempest user dir for RPM tempest

Create tempest.dir, use script to copy/link tempest contents into
tempest.dir before running config generate, modify
tempest_config_generate_command.

Change-Id: If1983a8e75f0f9e8827820d37cfbc4d1abad27dc
Adjust sudo use in tempest plays

Change-Id: Ibca898beadeeff199ba3ae777291e976cd82f540