Merge pull request #234 from anatoliychakkaev/master

Documentation in man and html
Defaults test and fixes

When property type is "undefined" - apply default value
Merge branch 'master' of github1602:1602/jugglingdb
Makefile for mocha testing
Started docs for model, changelog
Rewrite hooks API

This commit breaks compatibility, but adds consistent API and allow modify data of update
Rename essentials
Upd memory adapter to work with undefined in dataset
Remove old hooks tests
Minor test amends