Summary: Test DBOptionsAllFieldsSettable sometimes fails under valgrind. Move option settable tests to a separate test file and disable it in valgrind..

Test Plan: Run valgrind test and make sure the test doesn't run.

Reviewers: andrewkr, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: kradhakrishnan, yiwu, yhchiang, leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D56529