Extended the evaluator_spec.rb test suite.

We are now able to check if our index suggestions are really useful.
The test suite queries MongoDB for query performance stats and checks
if our indexes improve them.
Enhanced index suggestions, fixed a few bugs.

Proper indexes are now suggested for sorting purposes.
Evaluating existing indexes was also improved.
A few minor bugs were discovered and fixed.
Coding style improvements

Conformed to the Github Ruby Styleguide.
Removed constants from EfficiencyResult and IndexResult classes.
Bug fix: expect explain[scanAndOrder] to be false

Somehow explain["scanAndOrder"] returns false instead of nil on the server,
this commit is fixing this issue.
Removed the side effects of ensureIndexQuality

Dropping the newly created index inside ensureIndexQuality method.
Merge pull request #57 from jonasz/work

Extended test suite, enhanced index suggestions, conformed to the style guidelines
minor: moving to .ruby-version, killing .powrc
minor: adding license information, never go into battle without a shield
minor: spork, gemfile cleanup
Imporve result model & Support composite queries
**Changes**

* `EfficencyResult` and `IndexResult` are now store in separate field

* Add handler for `$mod` operator.

* Support recommend indexes for queries which contain `$or`, `$nor`, `$and` operators
[When using indexes with $or queries, each clause of an $or query will execute in parallel. These clauses can each use their own index.](http://docs.mongodb.org/manual/reference/operator/or/#_S_or) Thus, index suggestion function will generate index for each clause rather than a compound index for whole query.

* Modify some test cases to make it more rigorous

* Add test cases for new features
Merge pull request #58 from macworld/master

Imporve result model & Support composite queries
minor: bumping rails for security fix
refactor javascript
Merge branch 'master' of git://github.com/brandonblack/mongo-tools