Implements skip and limit for find.
Merge pull request #3 from vladlosev/feat-skip-and-limit

Implements skip and limit for find.
Implements better filtering (no date support yet).
Adds date support.
Removes obsolete test.
Adds support for dates and ObjectIDs. and removes old filter implemetation.
Fixes message and adds test for unknown top-level operator.
Adds user query error reporting in wire responses.
Streamlines code per reviewer's suggestions.
Adds tests for logical operator validation.
More lodash conversions.