Feature/date scripts

This includes the code from #2161 

This adds a link to the script fields listing that will populate a bunch of example date scripts for each date field, including:

```
__minuteOfHour
__minuteOfDay
__hourOfDay
__dayOfWeek
__dayOfMonth
__dayOfYear
__weekOfMonth
__weekOfYear
__monthOfYear
__quarterOfYear
```

It also adds a handy-dandy whirlwind intro to scripting to the scripted field creation page.
Since you know what field failed here, it might be useful to tell the user what field(s) are not being created.