Now information for Most Popular/Last Used Palette group stored as project properties. But palette models for different files from the same project are separate. They need to be synchronized.

Test case:
EXECUTE:
1. Create project test, create files a.html and b.html in the project
2. Open both files in Visual Page Editor
3. Insert few items from HTML5 Palette to the editor for a.html

ASSERT:
Most Popular/Last Used palette group shows items inserted in a.html page

EXECUTE:
1. Switch on b.html editor

ASSERT:
Most Popular/Last Used palette group shows items inserted in a.html page

FAIL: Most Popular/Last Used palette group is empty