integrating patch from AquaFold

- getMemInfo() implementation and a few minor tweaks to code provided by AquaFold now integrated including basic unit test coverage
- adding Intellij IDEA project files to .gitignore
integrated patch from AquaFold

- adding storage of a reference to the last com.mongodb.DB object used to the owning MongoScope for db.getLastError() calls after-the-fact (otherwise breaks fsync tests)
updated for 2.4.6

- minor threading(?) related bug fix around bsonsize()
- updated to use mongo-java-driver 2.11.3
- javascript APIs and jstests from mongo project copied over
Merge branch 'master' into develop

Conflicts:
	README.md
[maven-release-plugin] prepare release v1.3