Merge pull request #93 from admpub/dev

bug fixed
flatten the drivers dir
flatten caches dir
Method In provides a update string
Method In provides a update string
Method In provides a update string
Method In provides a update string
Added NewDB(), DB(), Clone() and removed pool object and other improvements
Merge branch 'dev' of https://github.com/unphp/xorm into unphp-dev
move Inc() to Incr()
update API comments
Merge pull request #6 from go-xorm/dev

update Dev