Upgrade LevelDB to 1.10.0, mostly for better write stall logging.
CondVar::SignalAll was broken, leading to deadlocks on Windows builds.
http://code.google.com/p/leveldb/issues/detail?id=149
LevelDB issue 178 fix: cannot resize a level 0 compaction set
Release leveldb 1.11

Fixes issues
161
174
178

As well as the issue reported by edouarda14@gmail.com about
MissingSSTFile unit test failing on windows.

Conflicts:
	Makefile
Release leveldb 1.12

Non-functional changes only:
1) Add Kevin Regan to the AUTHORS file
2) Add standard license header to issues/issue178_test.cc
Added GNU/kFreeBSD kernel name (TARGET_OS)

uname -s returns "GNU/kFreeBSD" on Debian GNU/kFreeBSD port. See http://www.debian.org/ports/kfreebsd-gnu/