Fix filter so logical operations are constructed correctly

[jazdw]

See the following gist for what this fixes. Also allows for nicer filter.or({key: value}) type filtering.

https://gist.github.com/jazdw/2410f64b99fbd9c104fa

[jazdw]

Note that #121 is related, perhaps sort and limit should be added to Filter as another operator type (so you would create them as filter.limit(10,20) for example) and then the whole query log could just be joined using filterCreator('and').apply(Filter.prototype, queryLog)

[kriszyp]

This looks like an excellent improvement to filtering. However, it looks like a unit testing is failing. Would you mind taking a look at the failing unit test?

[kriszyp]

Or is this dependent on #121 to address the unit test failure?

[jazdw]

Hey Kris, the or method will work slightly differently now. I've fixed the unit test. I think it reads more naturally?
condition1.or(condition2) => OR(condition1, condition2)
condition1.or(condition2, condition3) => OR(condition1, condition2, condition3)
instead of
condition1.or(condition2) => AND(condition1, OR(condition2))
condition1.or(condition2, condition3) => AND(condition1, OR(condition2, condition3))

[kriszyp]

Looks good, thank you!