v0.8.0.0330: Move some codes to statement sub package

Move some codes to statement sub package

Revert change for delete

Refactor new engine

Fix tests

Improve quote policy

Names with upper charactor on postgres will need quotes

Fix bug

Add new quote parameter on tests

Fix tests

Fix quotes

Improve quote policy

Fix cache bug

Fix map with cols

Fix rows bug

Improve dialect interface

Return sqls for create table

Code improvement

Fix find alias bug

Improve insert

Only replace quotes when necessary

Move value2interface from session to statement package

Remove duplicated code

Fix mssql issue with duplicate columns.

Fix err，add postgres column ARRAY

Fix table name

Ignore schema when dbtype is not postgres

Support count with cols

Fix bug when dump

Fix batch insert interface slice be panic

Fix master/slave bug

Fix pk bug

Fix dump/import bug 

Fix setschema

Fix dump bug 

Oracle : Local Naming Method

Stop using github.com/xorm/core

Fix find and count bug

Move processor function into one file

Fix duplicated deleted condition on FindAndCount

Don't keep db on dialects

Add more tests for FindAndCount

Fix dump test

Fix postgres schema problem

Fix quote with blank

Fix lint errors

Move column string to standalone method

Support session id

Improve insert map generating SQL

Move all integrations tests to a standalone sub package