Code review comment for lp:~jamesodhunt/upstart/bug-1315060

As implemented here: if i place foo.conf in both --confdir /etc/init --append-confdir /usr/share/upstart/system, the /etc/init/foo.conf will win.

Which I interpret to be opposite of "append" as in last one wins / "Last In First Out", and opposite of what was requested:
""
As for session jobs, I assume we can just set /custom as an XDG_CONFIG_DIR, and have /custom/upstart with jobs there.
""

In session init if foo.conf exists in both /usr/share/upstart/session and XDG_CONFIG_DIR/upstart, the "override" location XDG_CONFIG_DIR/upstart/foo.conf wins.