Make scoping clearer so Pyflakes can warn me about it.  Fix an issue where postgresUID/postgresGID wasn't set when we're not spawning postgres.
Make scoping clearer so Pyflakes can warn me about it.  Fix an issue where postgresUID/postgresGID wasn't set when we're not spawning postgres.

git-svn-id: 81e381228600e5752b80483efd2b45b26c451ea2@6617 e27351fd-9f3e-4f54-a53b-843176b1656c

trevor/calendarserver,trevor/calendarserver,trevor/calendarserver