Replace validation to node built-in functions
Change class name
Revert "Replace validation to node built-in functions"

This reverts commit 9e4ff9f9d1dfa10098ec9fdbcd44420e2af64332.
Compile the JavaScript without the top-level function
findById now use internal find method
Remove unnecessary return calls
Easymongo can works with id property, not only _id
Add tests for db and collection
Add more tests