Bump verison number to 3.7

Summary: As tittle

Test Plan: N/A

Reviewers: ljin, yhchiang, rven, igor

Reviewed By: igor

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D28299
fix the asan check

Summary: as title

Test Plan: ran it

Reviewers: yhchiang, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D28311
SetOptions() to return status and also add it to StackableDB

Summary: as title

Test Plan: ./db_test

Reviewers: sdong, yhchiang, rven, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D28269
Note dynamic options in options.h

Summary: as title

Test Plan: n/a

Reviewers: igor, yhchiang, rven, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D28287
Apply InfoLogLevel to the logs in util/env_hdfs.cc

Summary: Apply InfoLogLevel to the logs in util/env_hdfs.cc

Test Plan: make

Reviewers: ljin, sdong, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D28011