Fix copyright year

Fix outdated copyright year (update to 2014)

The copyright year was out of date. Copyright notices must reflect the current year. This commit updates the listed year to 2014.

see: http://www.copyright.gov/circs/circ01.pdf for more info
Fix warning on Mac OS
Fix HashSkipList and HashLinkedList SIGSEGV

Summary:
Original Summary:
Yesterday, @ljin and I were debugging various db_stress issues. We suspected one of them happens when we concurrently call NewIterator without prefix_seek on HashSkipList. This test demonstrates it.

Update:
Arena is not thread-safe!! When creating a new full iterator, we *have* to create a new arena, otherwise we're doomed.

Test Plan: SIGSEGV and assertion-throwing test now works!

Reviewers: ljin, haobo, sdong

Reviewed By: sdong

CC: leveldb, ljin

Differential Revision: https://reviews.facebook.net/D16857
Fix another Mac OS warning
unterminated conditional directive
Missing includes
Merge pull request #97 from agchou/patch-1

Fix copyright year
journal log_number correctly in MANIFEST

Summary:
Here is what it can cause probelm:
There is one memtable flush and one compaction. Both call LogAndApply(). If both edits are applied in the same batch with flush edit first and the compaction edit followed. LogAndApplyHelper() will assign compaction edit current VersionSet's log number(which should be smaller than the log number from flush edit). It cause log_numbers in MANIFEST to be not monotonic increasing, which violates the assume Recover() makes. What is more is after comitting to MANIFEST file, log_number_ in VersionSet is updated to the log_number from the last edit, which is the compaction one. It ends up not updating the log_number.

Test Plan:
make whitebox_crash_test
got another assertion about iter->valid(), not sure if that is related
to this.

Reviewers: igor, haobo

Reviewed By: igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16875
fix: use the correct edit when comparing log_number

Summary:
In the last fix, I forgot to point to the writer when comparing edit,
which is apparently not correct.

Test Plan: still running make whitebox_crash_test

Reviewers: igor, haobo, igor2

Reviewed By: igor2

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16911