contains -> containsKey with backwards compatible method.
Add @deprecated annotation to contains().
Fix comment.
Fix int64 operator== to not crash when comparing weird types.
Merge pull request #38 from alxhub/entity-contains-fix

contains -> containsKey with backwards compatibility.
Unit test for int64 ==.
Merge pull request #39 from alxhub/fix-fixnum

Fix int64 operator== to not crash when comparing weird types.