Remove duplicated code in DateField
Don't request focus on the first field on the tree edit and filter screens
Fix linty comment
Add initial step for adding collection UDFs.

Collection UDFs are now shown on the edit screen.
The first step of adding allows you to choose which model to add to.
Added JSONHelper class
Add choice fields to collection UDF add steps

Also:
 - Adds a next button in the ActionBar to move between steps
 - Renames drawables to reflect more general use
Add date field supports to collection UDF add steps
Show collection UDFs on the edit screen when added, save them with the tree
Swap JSONObjects everwhere for a real Model
Add ability to enter Alerts

 - Display fields in edit mode when in edit mode (Alerts)
 - Retain selected styling in choice fragments
Set action bar label based on the current step in UDF creation
code reformat
lint removal
PR cleanups:

 - better names
 - comments
 - remove unused method
 - string extraction
 - style fixes
 - Don't hide fields that are hidden in XML
 - Don't set field values unless there is a value to set
 - Show action bar label on first choice screen
Merge pull request #166 from maurizi/new-editable-collection-udf

Add ability to enter new collection UDFs and edit saved collection UDFs