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.
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
Merge https://code.google.com/p/leveldb