Apply level zero (no section) defaults for suite.rc.

For suite definitions we do not load all default values at once, in
order to leave a sparse runtime structure for efficient inheritance.
However, in loading defaults for everything but [runtime] I had
neglected to load the top level non-section defaults (just title and
description).
fix oops in previous commit.
Merge pull request #636 from hjoliver/suiterc-level0-defaults

Apply level zero (no section) defaults for suite.rc.