BulkInsert and group by on select

Add a bulk insert to insert a list of objects.
It will open only one transaction for it.

* bulkInsert(string table, [object fields], boolean replace)

Change the select All to have a group by

* selectAll(string tableName, [string column])
Update readme
Merge branch 'master' of https://github.com/Coleim/angular-websql

Conflicts:
	angular-websql.js