Fix for #14.
Fix RSpec deprecation warning.
Import lmdb 0.9.12 source.
Fix part of #11: cursor without block or cur txn is error.
Fix part of #11: transactions track and close cursors.
Merge pull request #15 from vjoel/fix-issue-14

Fix for #14.
Merge pull request #16 from vjoel/fix-rspec-deprecation

Fix rspec deprecation
Merge pull request #17 from vjoel/lmdb-0.9.12

Lmdb 0.9.12
Merge pull request #18 from vjoel/fix-issue-11

Fix issue 11