Merge pull request #128 from ahall/master

Satisfies the issue mentioned in #110.
bug fixed
ShowSQL bug fixed
Merge branch 'master' of github.com:go-xorm/xorm
add Sync2 for a new sync database struct methods
Merge branch 'bug'
pqsql-uuid
Merge pull request #133 from tossp/pqsql-uuid-pk

添加pgsql对uuid的支持
bug fixed for joinstr when has two Join
Merge branch 'master' of github.com:go-xorm/xorm
postgres uuid bug fixed
Update xorm.go

增加对https://github.com/denisenkom/go-mssqldb的适配，go-mssqldb对mssql数据库兼容支持较odbc好
Update engine.go

当数据库driver是https://github.com/denisenkom/go-mssqldb时，不对datetime类型进行时间截取，在go-mssqldb中会自动处理
Merge pull request #137 from wulove/patch-1

Update xorm.go
add mssql driver support
Merge branch 'master' of github.com:go-xorm/xorm
bugfix: getting the right column lines when the culumn type is varchar (n) or number (n, m)
improved docs
Merge pull request #138 from eryx/master

bugfix: getting the right column lines
bug fixed #139