Implementing deferred chaining.

**NOTE:** this does *not* implement defferred *nesting*
Rewrite of Deferred implementation and tests

Deferred is now inspired by jQuery implementation with some differences.

Tests for Deferred added
Using another Deferred implementation
Updating implementation to work with result chain
Updating Deferred implementation

Now handles method chaining and chained callbacks
Updating README about implementation
Merging method chain
Mongoise tests/empty find handling