Changed cmake policy for finding packages: Now path specified via -D<Packagename>_ROOT=/path/to/package/ are automatically considered when searching for packages.

CMakeLists.txt

@@ -1,6 +1,13 @@
 cmake_minimum_required (VERSION 3.2)
+
 cmake_policy(VERSION 3.2)
 
+# When searching for packages, we would like to first search in prefixes specified by <PackageName>_ROOT.
+# However, this behavior is only supported since CMake 3.12.
+if(POLICY CMP0074)
+	cmake_policy(SET CMP0074 NEW)
+endif()
+
 # Set project name
 project (storm CXX C)