COMP: Add cmake_minimum_required back

This reverts partially commit 111cb4e2e427ec6264956180579ecb95f251decf.
cmake_minimum_required is needed for each single example, as each example can be built separately from the whole projet.
The Required version was set to 2.8.5

Change-Id: Id8c2df0e705add80eacb911cfa4433a8031194dc
Merge "COMP: Add cmake_minimum_required back"