Add support for basic type pointer fields

Allows models like:

```
type User struct {
	Id    int64
	Name  string
	Email *string `orm:"null"`
}
```

This helps a lot when doing JSON marshalling/unmarshalling.

Pointer fields should always be declared with the NULL orm tag for sanity, this
probably requires documentation.
Update README
Merge pull request #764 from smallfish/master

Update README
Merge pull request #762 from pdf/pointer_field_support

Add support for basic type pointer fields
toolbox: fix the go routine asleep
refactor
utils: fix the SliceIntersect
httplib: set the default proto
fixed bug-request dump too early
Merge remote-tracking branch 'upstream/develop' into develop

Conflicts:
	httplib/httplib.go
bug fixed
Merge pull request #767 from JessonChan/develop

bug fixed