SharePoint 2013 app automatically split into two features

Hi

I have an App for SharePoint solution created in Visual Studio 2013.  I have declaratively created site columns, content types and two list definitions and instances.  Originally all solution items were in one web scoped Feature (Feature1).

When I closed and reopened the solution, Visual Studio has automatically split the solution into two Features (Feature1 and Feature2).  Deleting Feature2 and adding all items to Feature1 does not work as Feature2 reappears at the next solution close/open.

I suspect it has something to do with a lookup (site) column that relates one list instance to the other.  Feature2 holds the source list definition and instance for the lookup.  The only non-standard thing I did was, following a tip, I included the lookup column definition in the source list instance elements.xml to preclude empty data due to load order.

<?xml version="1.0" encoding="utf-8"?><Elements xmlns="http://schemas.microsoft.com/sharepoint/"><ListInstance Title="Common Names" OnQuickLaunch="TRUE" TemplateType="100" Url="Lists/CommonNames" Description="source for Common Names column"><Data>      ...    </Data></ListInstance><Field
    ID="{44c5e6fc-7f09-40b5-afc2-9e189ad6311c}"
    Name="CommonName"
    DisplayName="Common Name"
    Type="Lookup"
    List="Lists/CommonNames"
    ShowField="Title"
    Group="ABC"></Field></Elements>

I would like to understand why Visual Studio insists on creating two Features?

Thanx

Fox4