Default to "True" and "False" for bool options.

Summary:
Rather than throwing if we don't setOptions(), let's just default to true
and false.

Test Plan:
Removed a setOptions() call temporarily and saw options default to
true / false.

Reviewers: epriestley, btrahan, chad

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T2255

Differential Revision: https://secure.phabricator.com/D4368