[cmake-warning-fix][cmake-3.0-policy-CMP0043]

CMake 3.0 introduced policy CMP0043 which ignores the use of
COMPILE_DEFINITIONS_ suffixed variables, set policy behavior to OLD for
compatibility with version >3.0.
[cmake-warning-fix][cmake-3.0-policy-CMP0042]
Merge pull request #508 from tpaviot/review/cmake-policy-0043-fix

Fix CMake 3.0 warning about policy CMP0043