Applying the same style fixes as in #19: Running goimports (https://github.com/bradfitz/goimports) and Fatal(err) instead of Fatalf(err.Error())

Separated stdlib imports from other imports.

In all the mysql and sqlite and postgresql wrapper,fun toInternal in collection.go.

Reserved to the millisecond:
```
return fmt.Sprintf(TimeFormat, int(t/time.Hour), int(t/time.Minute%60), int(t/time.Second%60), t%time.Second/time.Millisecond)
```