Refactoring louloulibs and cmake

Use OBJECT libraries
Remove the louloulibs directory
Write FOUND variables in the cache

src/utils/revstr.cpp

@@ -0,0 +1,9 @@
+#include <utils/revstr.hpp>
+
+namespace utils
+{
+  std::string revstr(const std::string& original)
+  {
+    return {original.rbegin(), original.rend()};
+  }
+}