Support installation of Upstart v1.8 scripts

- Modify webos_build_daemon to detect *.conf.in files and install
  them to the correct directory for Upstart v1.8
- Update REFERENCE.md to reflect the new behavior

[GF-6056] Modify cmake-modules-webos to install upstart 1.8 *.conf files

Open-webOS-DCO-1.0-Signed-off-by: Keith Derrick <keith.derrick@lge.com>

Change-Id: I4d579740bb701a096b002543579004094d3dd092