Fix leak in c_test
Fix db_test and DBIter

Summary: Fix old issue with DBTest.Randomized with BlockBasedTableWithWholeKeyHashIndex + added printing in DBTest.Randomized.

Test Plan: make all check

Reviewers: zagfox, igor, ljin, yhchiang, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D21003
Fix SIGSEGV in travis

Summary:
Travis build was failing a lot. For example see https://travis-ci.org/facebook/rocksdb/builds/31425845

This fixes it.

Also, please don't put any code after SignalAll :)

Test Plan: no more SIGSEGV

Reviewers: yhchiang, sdong, ljin

Reviewed By: ljin

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D21417
Need to schedule compactions when manual compaction finishes

Summary: If there is an outstanding compaction scheduled but at the time a manual compaction is triggered, the manual compaction will preempt. In the end of the manual compaction, we should try to schedule compactions to make sure those preempted ones are not skipped.

Test Plan: make all check

Reviewers: yhchiang, ljin

Reviewed By: ljin

Subscribers: leveldb, dhruba, igor

Differential Revision: https://reviews.facebook.net/D21321
Include candidate files under options.db_log_dir in FindObsoleteFiles()

Summary: In FindObsoleteFiles(), we don't scan db_log_dir. Add it.

Test Plan: make all check

Reviewers: ljin, igor, yhchiang

Reviewed By: yhchiang

Subscribers: leveldb, yhchiang

Differential Revision: https://reviews.facebook.net/D21429