fix left join

• fix left join - #327
• make altertable property optional

fix multiEntry query issue with multiple column query

#319

Fix autoincrement in database schema upgrade

• Fix autoincrement in database schema upgrade

Fix issue with worker error message

• Fix issue with worker error message

Add check for workerRef not null

*Add check for workerRef not null

add list aggregate option

add list aggregate option

Allow as column to be queried in case of left join

Allow as column to be queried in case of left join

Fix left join with where

Fix left join with where - #306

fix issue with skip returning wrong no of results

fix issue with skip returning wrong no of results -

Fix without web worker issue

#296