more refactoring to be compatible with extended tests

Needed by:
Change-Id: If3346371a0e3e43490cad0f322f7913a64a3fd8f

- removed unnecessary/unused extra model class ImageMin
- renamed image property id to id_
- rebased with dependency
- some fixes to make extended tests work

Change-Id: I86a280cf3d186876da9dbd44c8099aac87cf56c3
Merge "more refactoring to be compatible with extended tests"