RocksDB static build
Make file changes to download and build the dependencies
.Load the shared library when RocksDB is initialized
Reverting import change
Addressing review comments
Remove TODO for checking index checksums
re-enable BlockBasedTable::SetupForCompaction()

Summary:
It was commented out in D22545 by accident. Keep the option in
ImmutableOptions for now. I can make it dynamic in
https://reviews.facebook.net/D23349

Test Plan: make release

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23865
Addressing review comments
Addressing review comments (adding a env variable to override temp directory)
Addressing review comments
Resolving merge conflict
Merge pull request #309 from naveenatceg/staticbuild

RocksDB Staticbuild
Enlarge log size cap when printing file summary

Summary:
Now the file summary is too small for printing. Enlarge it.
To enable it, allow to pass a size to log buffer.

Test Plan:
Add a unit test.
make all check

Reviewers: ljin, yhchiang

Reviewed By: yhchiang

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D21723