Browser database API adapter

An browser database API adapter and wrapper which as a adapter selects the available browser database API i.e. IndexedDB or WebSQL for inserting data, and as a wrapper provide simplified methods for accessing IndexedDB or WebSQL API.

This adapter is a schema oriented adapter which unlike many other open source adapter and wrappers, lets us define and database schema and work on it. Using database schema can help to manage the offline data in efficient and powerful way.
This adapter doesn't work without defining database schema. User has to define a database and at-least one table for storing data.

Preferred database API is IndexedDB and then WebSQL. This means that if IndexedDB is present then it would be used for database access otherwise WebSQL will be used.