Clean & modernize LIEF code base

This commit (obviously non-atomic) cleans LIEF's code base by:
  - Using pointer semantics (`std::unique_ptr<>`)
  - Using LEAF boost error in the binary stream
  - Reducing the scope of the iterators (`it_section`, ...)
  - Removing `Structures.hpp` from the public headers
  - etc

api/python/MachO/objects/pyDataInCode.cpp

@@ -21,6 +21,7 @@
 #include "LIEF/MachO/hash.hpp"
 #include "LIEF/MachO/DataInCode.hpp"
 
+#include "pyIterators.hpp"
 #include "pyMachO.hpp"